1098 lines
34 KiB
C++
1098 lines
34 KiB
C++
// Dual OpenGL 3.2 and OpenGL ES 2.0 renderer
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#include "../Rendering.h"
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#include <stddef.h>
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#include <stdlib.h>
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#include <string.h>
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#ifdef USE_OPENGLES2
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#include <GLES2/gl2.h>
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#else
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#include <glad/glad.h>
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#endif
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#define SPRITEBATCH_IMPLEMENTATION
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#include "../../../external/cute_spritebatch.h"
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#include "../Misc.h"
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#include "Window/OpenGL.h"
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#define TOTAL_VBOS 8
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#define ATTRIBUTE_INPUT_VERTEX_COORDINATES 1
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#define ATTRIBUTE_INPUT_TEXTURE_COORDINATES 2
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typedef enum RenderMode
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{
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MODE_BLANK,
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MODE_DRAW_SURFACE,
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MODE_DRAW_SURFACE_WITH_TRANSPARENCY,
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MODE_COLOUR_FILL,
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MODE_DRAW_GLYPH
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} RenderMode;
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typedef struct RenderBackend_Surface
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{
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GLuint texture_id;
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unsigned int width;
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unsigned int height;
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unsigned char *pixels;
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} RenderBackend_Surface;
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typedef struct RenderBackend_Glyph
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{
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unsigned char *pixels;
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unsigned int width;
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unsigned int height;
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unsigned int pitch;
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} RenderBackend_Glyph;
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typedef struct Coordinate2D
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{
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GLfloat x;
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GLfloat y;
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} Coordinate2D;
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typedef struct Vertex
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{
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Coordinate2D position;
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Coordinate2D texture;
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} Vertex;
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typedef struct VertexBufferSlot
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{
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Vertex vertices[2][3];
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} VertexBufferSlot;
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static GLuint program_texture;
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static GLuint program_colour_fill;
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static GLuint program_glyph;
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static GLint program_colour_fill_uniform_colour;
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static GLint program_glyph_uniform_colour;
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#ifndef USE_OPENGLES2
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static GLuint vertex_array_id;
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#endif
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static GLuint vertex_buffer_ids[TOTAL_VBOS];
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static GLuint framebuffer_id;
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static VertexBufferSlot *local_vertex_buffer;
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static unsigned long local_vertex_buffer_size;
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static unsigned long current_vertex_buffer_slot;
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static RenderMode last_render_mode;
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static GLuint last_source_texture;
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static GLuint last_destination_texture;
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static RenderBackend_Surface framebuffer;
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static unsigned char glyph_colour_channels[3];
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static RenderBackend_Surface *glyph_destination_surface;
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static spritebatch_t glyph_batcher;
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static int actual_screen_width;
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static int actual_screen_height;
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#ifdef USE_OPENGLES2
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static const GLchar *vertex_shader_plain = " \
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#version 100\n \
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attribute vec2 input_vertex_coordinates; \
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void main() \
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{ \
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gl_Position = vec4(input_vertex_coordinates.xy, 0.0, 1.0); \
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} \
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";
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static const GLchar *vertex_shader_texture = " \
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#version 100\n \
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attribute vec2 input_vertex_coordinates; \
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attribute vec2 input_texture_coordinates; \
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varying vec2 texture_coordinates; \
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void main() \
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{ \
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texture_coordinates = input_texture_coordinates; \
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gl_Position = vec4(input_vertex_coordinates.xy, 0.0, 1.0); \
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} \
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";
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static const GLchar *fragment_shader_texture = " \
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#version 100\n \
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precision mediump float; \
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uniform sampler2D tex; \
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varying vec2 texture_coordinates; \
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void main() \
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{ \
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gl_FragColor = texture2D(tex, texture_coordinates); \
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} \
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";
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static const GLchar *fragment_shader_colour_fill = " \
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#version 100\n \
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precision mediump float; \
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uniform vec4 colour; \
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void main() \
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{ \
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gl_FragColor = colour; \
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} \
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";
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static const GLchar *fragment_shader_glyph = " \
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#version 100\n \
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precision mediump float; \
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uniform sampler2D tex; \
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uniform vec4 colour; \
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varying vec2 texture_coordinates; \
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void main() \
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{ \
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gl_FragColor = colour * texture2D(tex, texture_coordinates).r; \
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} \
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";
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#else
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static const GLchar *vertex_shader_plain = " \
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#version 150 core\n \
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in vec2 input_vertex_coordinates; \
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void main() \
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{ \
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gl_Position = vec4(input_vertex_coordinates.xy, 0.0, 1.0); \
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} \
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";
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static const GLchar *vertex_shader_texture = " \
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#version 150 core\n \
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in vec2 input_vertex_coordinates; \
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in vec2 input_texture_coordinates; \
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out vec2 texture_coordinates; \
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void main() \
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{ \
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texture_coordinates = input_texture_coordinates; \
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gl_Position = vec4(input_vertex_coordinates.xy, 0.0, 1.0); \
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} \
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";
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static const GLchar *fragment_shader_texture = " \
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#version 150 core\n \
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uniform sampler2D tex; \
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in vec2 texture_coordinates; \
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out vec4 fragment; \
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void main() \
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{ \
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fragment = texture(tex, texture_coordinates); \
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} \
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";
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static const GLchar *fragment_shader_colour_fill = " \
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#version 150 core\n \
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uniform vec4 colour; \
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out vec4 fragment; \
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void main() \
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{ \
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fragment = colour; \
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} \
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";
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static const GLchar *fragment_shader_glyph = " \
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#version 150 core\n \
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uniform sampler2D tex; \
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uniform vec4 colour; \
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in vec2 texture_coordinates; \
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out vec4 fragment; \
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void main() \
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{ \
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fragment = colour * texture(tex, texture_coordinates).r; \
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} \
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";
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#endif
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/*
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static void GLAPIENTRY MessageCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void* userParam)
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{
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(void)source;
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(void)type;
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(void)id;
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(void)length;
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(void)userParam;
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if (severity != GL_DEBUG_SEVERITY_NOTIFICATION)
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Backend_PrintInfo("OpenGL debug: %s", message);
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}
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*/
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////////////////////////
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// Shader compilation //
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////////////////////////
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static GLuint CompileShader(const char *vertex_shader_source, const char *fragment_shader_source)
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{
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GLint shader_status;
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GLuint program_id = glCreateProgram();
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// Compile vertex shader
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GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
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glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL);
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glCompileShader(vertex_shader);
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glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &shader_status);
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if (shader_status != GL_TRUE)
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{
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char buffer[0x200];
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glGetShaderInfoLog(vertex_shader, sizeof(buffer), NULL, buffer);
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Backend_ShowMessageBox("Vertex shader error", buffer);
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return 0;
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}
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glAttachShader(program_id, vertex_shader);
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// Compile fragment shader
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GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
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glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL);
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glCompileShader(fragment_shader);
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glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &shader_status);
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if (shader_status != GL_TRUE)
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{
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char buffer[0x400];
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glGetShaderInfoLog(fragment_shader, sizeof(buffer), NULL, buffer);
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Backend_ShowMessageBox("Fragment shader error", buffer);
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return 0;
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}
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glAttachShader(program_id, fragment_shader);
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// Link shaders
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glBindAttribLocation(program_id, ATTRIBUTE_INPUT_VERTEX_COORDINATES, "input_vertex_coordinates");
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glBindAttribLocation(program_id, ATTRIBUTE_INPUT_TEXTURE_COORDINATES, "input_texture_coordinates");
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glLinkProgram(program_id);
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glGetProgramiv(program_id, GL_LINK_STATUS, &shader_status);
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if (shader_status != GL_TRUE)
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{
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char buffer[0x400];
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glGetProgramInfoLog(program_id, sizeof(buffer), NULL, buffer);
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Backend_ShowMessageBox("Shader linker error", buffer);
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return 0;
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}
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return program_id;
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}
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//////////////////////////////
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// Vertex buffer management //
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//////////////////////////////
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static VertexBufferSlot* GetVertexBufferSlot(unsigned int slots_needed)
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{
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// Check if buffer needs expanding
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if (current_vertex_buffer_slot + slots_needed > local_vertex_buffer_size)
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{
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local_vertex_buffer_size = 1;
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while (current_vertex_buffer_slot + slots_needed > local_vertex_buffer_size)
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local_vertex_buffer_size <<= 1;
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VertexBufferSlot *realloc_result = (VertexBufferSlot*)realloc(local_vertex_buffer, local_vertex_buffer_size * sizeof(VertexBufferSlot));
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if (realloc_result != NULL)
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{
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local_vertex_buffer = realloc_result;
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}
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else
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{
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Backend_PrintError("Couldn't expand vertex buffer");
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return NULL;
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}
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}
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current_vertex_buffer_slot += slots_needed;
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return &local_vertex_buffer[current_vertex_buffer_slot - slots_needed];
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}
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static void FlushVertexBuffer(void)
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{
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static unsigned long vertex_buffer_size[TOTAL_VBOS];
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static unsigned int current_vertex_buffer = 0;
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if (current_vertex_buffer_slot == 0)
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return;
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// Select new VBO
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glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_ids[current_vertex_buffer]);
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glVertexAttribPointer(ATTRIBUTE_INPUT_VERTEX_COORDINATES, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, position));
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glVertexAttribPointer(ATTRIBUTE_INPUT_TEXTURE_COORDINATES, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, texture));
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// Upload vertex buffer to VBO, growing it if necessary
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if (local_vertex_buffer_size > vertex_buffer_size[current_vertex_buffer])
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{
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vertex_buffer_size[current_vertex_buffer] = local_vertex_buffer_size;
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glBufferData(GL_ARRAY_BUFFER, vertex_buffer_size[current_vertex_buffer] * sizeof(VertexBufferSlot), local_vertex_buffer, GL_STREAM_DRAW);
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}
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else
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{
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glBufferSubData(GL_ARRAY_BUFFER, 0, current_vertex_buffer_slot * sizeof(VertexBufferSlot), local_vertex_buffer);
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}
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if (++current_vertex_buffer >= TOTAL_VBOS)
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current_vertex_buffer = 0;
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glDrawArrays(GL_TRIANGLES, 0, 6 * current_vertex_buffer_slot);
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current_vertex_buffer_slot = 0;
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}
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////////////////////
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// Glyph-batching //
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////////////////////
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// Blit the glyphs in the batch
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static void GlyphBatch_Draw(spritebatch_sprite_t *sprites, int count, int texture_w, int texture_h, void *udata)
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{
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static unsigned char last_red;
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static unsigned char last_green;
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static unsigned char last_blue;
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(void)texture_h;
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(void)udata;
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if (glyph_destination_surface == NULL)
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return;
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GLuint texture_id = (GLuint)sprites[0].texture_id;
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// Flush vertex data if a context-change is needed
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if (last_render_mode != MODE_DRAW_GLYPH || last_destination_texture != glyph_destination_surface->texture_id || last_source_texture != texture_id || last_red != glyph_colour_channels[0] || last_green != glyph_colour_channels[1] || last_blue != glyph_colour_channels[2])
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{
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FlushVertexBuffer();
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last_render_mode = MODE_DRAW_GLYPH;
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last_destination_texture = glyph_destination_surface->texture_id;
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last_source_texture = texture_id;
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last_red = glyph_colour_channels[0];
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last_green = glyph_colour_channels[1];
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last_blue = glyph_colour_channels[2];
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glUseProgram(program_glyph);
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glUniform4f(program_glyph_uniform_colour, glyph_colour_channels[0] / 255.0f, glyph_colour_channels[1] / 255.0f, glyph_colour_channels[2] / 255.0f, 1.0f);
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// Point our framebuffer to the destination texture
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glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, glyph_destination_surface->texture_id, 0);
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glViewport(0, 0, glyph_destination_surface->width, glyph_destination_surface->height);
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glEnable(GL_BLEND);
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// Enable texture coordinates, since this uses textures
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glEnableVertexAttribArray(ATTRIBUTE_INPUT_TEXTURE_COORDINATES);
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glBindTexture(GL_TEXTURE_2D, texture_id);
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}
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// Add data to the vertex queue
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VertexBufferSlot *vertex_buffer_slot = GetVertexBufferSlot(count);
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if (vertex_buffer_slot != NULL)
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{
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for (int i = 0; i < count; ++i)
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{
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RenderBackend_Glyph *glyph = (RenderBackend_Glyph*)sprites[i].image_id;
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const GLfloat texture_left = sprites[i].minx;
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const GLfloat texture_right = texture_left + ((GLfloat)glyph->width / (GLfloat)texture_w); // Account for width not matching pitch
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const GLfloat texture_top = sprites[i].maxy;
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const GLfloat texture_bottom = sprites[i].miny;
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const GLfloat vertex_left = (sprites[i].x * (2.0f / glyph_destination_surface->width)) - 1.0f;
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const GLfloat vertex_right = ((sprites[i].x + glyph->width) * (2.0f / glyph_destination_surface->width)) - 1.0f;
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const GLfloat vertex_top = (sprites[i].y * (2.0f / glyph_destination_surface->height)) - 1.0f;
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const GLfloat vertex_bottom = ((sprites[i].y + glyph->height) * (2.0f / glyph_destination_surface->height)) - 1.0f;
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vertex_buffer_slot[i].vertices[0][0].texture.x = texture_left;
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vertex_buffer_slot[i].vertices[0][0].texture.y = texture_top;
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vertex_buffer_slot[i].vertices[0][1].texture.x = texture_right;
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vertex_buffer_slot[i].vertices[0][1].texture.y = texture_top;
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vertex_buffer_slot[i].vertices[0][2].texture.x = texture_right;
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vertex_buffer_slot[i].vertices[0][2].texture.y = texture_bottom;
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vertex_buffer_slot[i].vertices[1][0].texture.x = texture_left;
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vertex_buffer_slot[i].vertices[1][0].texture.y = texture_top;
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vertex_buffer_slot[i].vertices[1][1].texture.x = texture_right;
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vertex_buffer_slot[i].vertices[1][1].texture.y = texture_bottom;
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vertex_buffer_slot[i].vertices[1][2].texture.x = texture_left;
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vertex_buffer_slot[i].vertices[1][2].texture.y = texture_bottom;
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vertex_buffer_slot[i].vertices[0][0].position.x = vertex_left;
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vertex_buffer_slot[i].vertices[0][0].position.y = vertex_top;
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vertex_buffer_slot[i].vertices[0][1].position.x = vertex_right;
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vertex_buffer_slot[i].vertices[0][1].position.y = vertex_top;
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vertex_buffer_slot[i].vertices[0][2].position.x = vertex_right;
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vertex_buffer_slot[i].vertices[0][2].position.y = vertex_bottom;
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vertex_buffer_slot[i].vertices[1][0].position.x = vertex_left;
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vertex_buffer_slot[i].vertices[1][0].position.y = vertex_top;
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vertex_buffer_slot[i].vertices[1][1].position.x = vertex_right;
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vertex_buffer_slot[i].vertices[1][1].position.y = vertex_bottom;
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vertex_buffer_slot[i].vertices[1][2].position.x = vertex_left;
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vertex_buffer_slot[i].vertices[1][2].position.y = vertex_bottom;
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}
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}
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}
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// Upload the glyph's pixels
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static void GlyphBatch_GetPixels(SPRITEBATCH_U64 image_id, void *buffer, int bytes_to_fill, void *udata)
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{
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(void)udata;
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RenderBackend_Glyph *glyph = (RenderBackend_Glyph*)image_id;
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memcpy(buffer, glyph->pixels, bytes_to_fill);
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}
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// Create a texture atlas, and upload pixels to it
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static SPRITEBATCH_U64 GlyphBatch_CreateTexture(void *pixels, int w, int h, void *udata)
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{
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(void)udata;
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GLuint texture_id;
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glGenTextures(1, &texture_id);
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glBindTexture(GL_TEXTURE_2D, texture_id);
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#ifdef USE_OPENGLES2
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glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, w, h, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, pixels);
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#else
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glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, pixels);
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#endif
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
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#ifndef USE_OPENGLES2
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
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#endif
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glBindTexture(GL_TEXTURE_2D, last_source_texture);
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return (SPRITEBATCH_U64)texture_id;
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}
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// Destroy texture atlas
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static void GlyphBatch_DestroyTexture(SPRITEBATCH_U64 texture_id, void *udata)
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{
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(void)udata;
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GLuint gl_texture_id = (GLuint)texture_id;
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// Flush the vertex buffer if we're about to destroy its texture
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// TODO - This leaves `last_source_texture`/`last_destination_texture` dangling
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if (gl_texture_id == last_source_texture || gl_texture_id == last_destination_texture)
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FlushVertexBuffer();
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|
|
glDeleteTextures(1, &gl_texture_id);
|
|
}
|
|
|
|
#ifndef USE_OPENGLES2
|
|
|
|
static const char* GetOpenGLErrorCodeDescription(GLenum error_code)
|
|
{
|
|
switch (error_code)
|
|
{
|
|
case GL_NO_ERROR:
|
|
return "No error";
|
|
|
|
case GL_INVALID_ENUM:
|
|
return "An unacceptable value was specified for enumerated argument";
|
|
|
|
case GL_INVALID_VALUE:
|
|
return "A numeric argument is out of range";
|
|
|
|
case GL_INVALID_OPERATION:
|
|
return "The specified operation is not allowed in the current state";
|
|
|
|
case GL_INVALID_FRAMEBUFFER_OPERATION:
|
|
return "The framebuffer object is not complete";
|
|
|
|
case GL_OUT_OF_MEMORY:
|
|
return "There is not enough memory left to execute the command";
|
|
|
|
/*
|
|
* For some reason glad does not define these even though they are there in OpenGL 3.2
|
|
*/
|
|
|
|
/*
|
|
case GL_STACK_UNDERFLOW:
|
|
return "An attempt has been made to perform an operation that would cause an internal stack to underflow";
|
|
|
|
case GL_STACK_OVERFLOW:
|
|
return "An attempt has been made to perform an operation that would cause an internal stack to overflow";
|
|
*/
|
|
|
|
default:
|
|
return "Unknown error";
|
|
}
|
|
}
|
|
|
|
static void PostGLCallCallback(const char *name, void *function_pointer, int length_arguments, ...)
|
|
{
|
|
(void)function_pointer;
|
|
(void)length_arguments;
|
|
|
|
GLenum error_code = glad_glGetError(); // Manually use glad_glGetError. Otherwise, glad_debug_glGetError would be called and we'd get infinite recursion into this function
|
|
|
|
if (error_code != GL_NO_ERROR)
|
|
Backend_PrintError("Error %d in %s: %s", error_code, name, GetOpenGLErrorCodeDescription(error_code));
|
|
}
|
|
|
|
#endif
|
|
|
|
///////////////////////////////////
|
|
// Render-backend initialisation //
|
|
///////////////////////////////////
|
|
|
|
RenderBackend_Surface* RenderBackend_Init(const char *window_title, int screen_width, int screen_height, bool fullscreen, bool *vsync)
|
|
{
|
|
#ifndef USE_OPENGLES2
|
|
glad_set_post_callback(PostGLCallCallback);
|
|
#endif
|
|
|
|
actual_screen_width = screen_width;
|
|
actual_screen_height = screen_height;
|
|
|
|
if (WindowBackend_OpenGL_CreateWindow(window_title, &actual_screen_width, &actual_screen_height, fullscreen, *vsync))
|
|
{
|
|
Backend_PrintInfo("GL_VENDOR = %s", glGetString(GL_VENDOR));
|
|
Backend_PrintInfo("GL_RENDERER = %s", glGetString(GL_RENDERER));
|
|
Backend_PrintInfo("GL_VERSION = %s", glGetString(GL_VERSION));
|
|
Backend_PrintInfo("GL_SHADING_LANGUAGE_VERSION = %s", glGetString(GL_SHADING_LANGUAGE_VERSION));
|
|
|
|
// We're using pre-multiplied alpha so we can blend onto textures that have their own alpha
|
|
// http://apoorvaj.io/alpha-compositing-opengl-blending-and-premultiplied-alpha.html
|
|
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
|
|
|
|
//glEnable(GL_DEBUG_OUTPUT);
|
|
//glDebugMessageCallback(MessageCallback, 0);
|
|
|
|
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
|
|
glClear(GL_COLOR_BUFFER_BIT);
|
|
|
|
#ifndef USE_OPENGLES2
|
|
// Set up Vertex Array Object
|
|
glGenVertexArrays(1, &vertex_array_id);
|
|
glBindVertexArray(vertex_array_id);
|
|
#endif
|
|
|
|
// Set up Vertex Buffer Objects
|
|
glGenBuffers(TOTAL_VBOS, vertex_buffer_ids);
|
|
|
|
// Set up the vertex attributes
|
|
glEnableVertexAttribArray(ATTRIBUTE_INPUT_VERTEX_COORDINATES);
|
|
|
|
// Set up our shaders
|
|
program_texture = CompileShader(vertex_shader_texture, fragment_shader_texture);
|
|
program_colour_fill = CompileShader(vertex_shader_plain, fragment_shader_colour_fill);
|
|
program_glyph = CompileShader(vertex_shader_texture, fragment_shader_glyph);
|
|
|
|
if (program_texture != 0 && program_colour_fill != 0 && program_glyph != 0)
|
|
{
|
|
// Get shader uniforms
|
|
program_colour_fill_uniform_colour = glGetUniformLocation(program_colour_fill, "colour");
|
|
program_glyph_uniform_colour = glGetUniformLocation(program_glyph, "colour");
|
|
|
|
// Set up framebuffer (used for surface-to-surface blitting)
|
|
glGenFramebuffers(1, &framebuffer_id);
|
|
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);
|
|
|
|
// Set up framebuffer screen texture (used for screen-to-surface blitting)
|
|
glGenTextures(1, &framebuffer.texture_id);
|
|
glBindTexture(GL_TEXTURE_2D, framebuffer.texture_id);
|
|
#ifdef USE_OPENGLES2
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, screen_width, screen_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
|
|
#else
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, screen_width, screen_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
|
|
#endif
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
|
|
#ifndef USE_OPENGLES2
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
|
|
#endif
|
|
|
|
framebuffer.width = screen_width;
|
|
framebuffer.height = screen_height;
|
|
|
|
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebuffer.texture_id, 0);
|
|
glViewport(0, 0, framebuffer.width, framebuffer.height);
|
|
|
|
// Set-up glyph-batcher
|
|
spritebatch_config_t config;
|
|
spritebatch_set_default_config(&config);
|
|
config.pixel_stride = 1;
|
|
config.atlas_width_in_pixels = 256;
|
|
config.atlas_height_in_pixels = 256;
|
|
config.lonely_buffer_count_till_flush = 4; // Start making atlases immediately
|
|
config.batch_callback = GlyphBatch_Draw;
|
|
config.get_pixels_callback = GlyphBatch_GetPixels;
|
|
config.generate_texture_callback = GlyphBatch_CreateTexture;
|
|
config.delete_texture_callback = GlyphBatch_DestroyTexture;
|
|
spritebatch_init(&glyph_batcher, &config, NULL);
|
|
|
|
return &framebuffer;
|
|
}
|
|
|
|
if (program_glyph != 0)
|
|
glDeleteProgram(program_glyph);
|
|
|
|
if (program_colour_fill != 0)
|
|
glDeleteProgram(program_colour_fill);
|
|
|
|
if (program_texture != 0)
|
|
glDeleteProgram(program_texture);
|
|
|
|
glDeleteBuffers(TOTAL_VBOS, vertex_buffer_ids);
|
|
#ifndef USE_OPENGLES2
|
|
glDeleteVertexArrays(1, &vertex_array_id);
|
|
#endif
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void RenderBackend_Deinit(void)
|
|
{
|
|
free(local_vertex_buffer);
|
|
|
|
spritebatch_term(&glyph_batcher);
|
|
|
|
glDeleteTextures(1, &framebuffer.texture_id);
|
|
glDeleteFramebuffers(1, &framebuffer_id);
|
|
glDeleteProgram(program_glyph);
|
|
glDeleteProgram(program_colour_fill);
|
|
glDeleteProgram(program_texture);
|
|
glDeleteBuffers(TOTAL_VBOS, vertex_buffer_ids);
|
|
#ifndef USE_OPENGLES2
|
|
glDeleteVertexArrays(1, &vertex_array_id);
|
|
#endif
|
|
|
|
WindowBackend_OpenGL_DestroyWindow();
|
|
}
|
|
|
|
void RenderBackend_DrawScreen(void)
|
|
{
|
|
spritebatch_tick(&glyph_batcher);
|
|
|
|
FlushVertexBuffer();
|
|
last_render_mode = MODE_BLANK;
|
|
last_source_texture = 0;
|
|
last_destination_texture = 0;
|
|
|
|
// This would be a good time to use a custom shader to divide the pixels by
|
|
// their alpha, to undo the premultiplied alpha stuff, but the framebuffer
|
|
// is pretty much guaranteed to be fully opaque, and X / 1 == X, so it'd be
|
|
// a waste of processing power.
|
|
|
|
glUseProgram(program_texture);
|
|
|
|
glDisable(GL_BLEND);
|
|
|
|
// Enable texture coordinates, since this uses textures
|
|
glEnableVertexAttribArray(ATTRIBUTE_INPUT_TEXTURE_COORDINATES);
|
|
|
|
// Target actual screen, and not our framebuffer
|
|
glBindFramebuffer(GL_FRAMEBUFFER, 0);
|
|
|
|
// Do some viewport trickery, to fit the framebuffer in the center of the screen
|
|
GLint x;
|
|
GLint y;
|
|
GLsizei width;
|
|
GLsizei height;
|
|
|
|
if (actual_screen_width * framebuffer.height > framebuffer.width * actual_screen_height) // Fancy way to do `if (actual_screen_width / actual_screen_height > framebuffer.width / framebuffer.height)` without floats
|
|
{
|
|
y = 0;
|
|
height = actual_screen_height;
|
|
|
|
width = (framebuffer.width * actual_screen_height) / framebuffer.height;
|
|
x = (actual_screen_width - width) / 2;
|
|
}
|
|
else
|
|
{
|
|
x = 0;
|
|
width = actual_screen_width;
|
|
|
|
height = (framebuffer.height * actual_screen_width) / framebuffer.width;
|
|
y = (actual_screen_height - height) / 2;
|
|
}
|
|
|
|
glViewport(x, y, width, height);
|
|
|
|
// Draw framebuffer to screen
|
|
glBindTexture(GL_TEXTURE_2D, framebuffer.texture_id);
|
|
|
|
VertexBufferSlot *vertex_buffer_slot = GetVertexBufferSlot(1);
|
|
|
|
if (vertex_buffer_slot != NULL)
|
|
{
|
|
vertex_buffer_slot->vertices[0][0].texture.x = 0.0f;
|
|
vertex_buffer_slot->vertices[0][0].texture.y = 1.0f;
|
|
vertex_buffer_slot->vertices[0][1].texture.x = 1.0f;
|
|
vertex_buffer_slot->vertices[0][1].texture.y = 1.0f;
|
|
vertex_buffer_slot->vertices[0][2].texture.x = 1.0f;
|
|
vertex_buffer_slot->vertices[0][2].texture.y = 0.0f;
|
|
|
|
vertex_buffer_slot->vertices[1][0].texture.x = 0.0f;
|
|
vertex_buffer_slot->vertices[1][0].texture.y = 1.0f;
|
|
vertex_buffer_slot->vertices[1][1].texture.x = 1.0f;
|
|
vertex_buffer_slot->vertices[1][1].texture.y = 0.0f;
|
|
vertex_buffer_slot->vertices[1][2].texture.x = 0.0f;
|
|
vertex_buffer_slot->vertices[1][2].texture.y = 0.0f;
|
|
|
|
vertex_buffer_slot->vertices[0][0].position.x = -1.0f;
|
|
vertex_buffer_slot->vertices[0][0].position.y = -1.0f;
|
|
vertex_buffer_slot->vertices[0][1].position.x = 1.0f;
|
|
vertex_buffer_slot->vertices[0][1].position.y = -1.0f;
|
|
vertex_buffer_slot->vertices[0][2].position.x = 1.0f;
|
|
vertex_buffer_slot->vertices[0][2].position.y = 1.0f;
|
|
|
|
vertex_buffer_slot->vertices[1][0].position.x = -1.0f;
|
|
vertex_buffer_slot->vertices[1][0].position.y = -1.0f;
|
|
vertex_buffer_slot->vertices[1][1].position.x = 1.0f;
|
|
vertex_buffer_slot->vertices[1][1].position.y = 1.0f;
|
|
vertex_buffer_slot->vertices[1][2].position.x = -1.0f;
|
|
vertex_buffer_slot->vertices[1][2].position.y = 1.0f;
|
|
}
|
|
|
|
FlushVertexBuffer();
|
|
|
|
WindowBackend_OpenGL_Display();
|
|
|
|
// According to https://www.khronos.org/opengl/wiki/Common_Mistakes#Swap_Buffers
|
|
// the buffer should always be cleared, even if it seems unnecessary
|
|
glClear(GL_COLOR_BUFFER_BIT);
|
|
|
|
// Switch back to our framebuffer
|
|
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);
|
|
}
|
|
|
|
////////////////////////
|
|
// Surface management //
|
|
////////////////////////
|
|
|
|
RenderBackend_Surface* RenderBackend_CreateSurface(unsigned int width, unsigned int height, bool render_target)
|
|
{
|
|
(void)render_target;
|
|
|
|
RenderBackend_Surface *surface = (RenderBackend_Surface*)malloc(sizeof(RenderBackend_Surface));
|
|
|
|
if (surface == NULL)
|
|
return NULL;
|
|
|
|
glGenTextures(1, &surface->texture_id);
|
|
glBindTexture(GL_TEXTURE_2D, surface->texture_id);
|
|
#ifdef USE_OPENGLES2
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
|
|
#else
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
|
|
#endif
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
|
|
#ifndef USE_OPENGLES2
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
|
|
#endif
|
|
|
|
glBindTexture(GL_TEXTURE_2D, last_source_texture);
|
|
|
|
surface->width = width;
|
|
surface->height = height;
|
|
|
|
return surface;
|
|
}
|
|
|
|
void RenderBackend_FreeSurface(RenderBackend_Surface *surface)
|
|
{
|
|
if (surface == NULL)
|
|
return;
|
|
|
|
// Flush the vertex buffer if we're about to destroy its texture
|
|
// TODO - This leaves `last_source_texture`/`last_destination_texture` dangling
|
|
if (surface->texture_id == last_source_texture || surface->texture_id == last_destination_texture)
|
|
FlushVertexBuffer();
|
|
|
|
glDeleteTextures(1, &surface->texture_id);
|
|
free(surface);
|
|
}
|
|
|
|
bool RenderBackend_IsSurfaceLost(RenderBackend_Surface *surface)
|
|
{
|
|
(void)surface;
|
|
|
|
return false;
|
|
}
|
|
|
|
void RenderBackend_RestoreSurface(RenderBackend_Surface *surface)
|
|
{
|
|
(void)surface;
|
|
}
|
|
|
|
unsigned char* RenderBackend_LockSurface(RenderBackend_Surface *surface, unsigned int *pitch, unsigned int width, unsigned int height)
|
|
{
|
|
if (surface == NULL)
|
|
return NULL;
|
|
|
|
surface->pixels = (unsigned char*)malloc(width * height * 4);
|
|
*pitch = width * 4;
|
|
|
|
return surface->pixels;
|
|
}
|
|
|
|
void RenderBackend_UnlockSurface(RenderBackend_Surface *surface, unsigned int width, unsigned int height)
|
|
{
|
|
if (surface == NULL)
|
|
return;
|
|
|
|
// Flush the vertex buffer if we're about to modify its texture
|
|
if (surface->texture_id == last_source_texture || surface->texture_id == last_destination_texture)
|
|
FlushVertexBuffer();
|
|
|
|
// Pre-multiply the colour channels with the alpha, so blending works correctly
|
|
unsigned char *pixels = surface->pixels;
|
|
|
|
for (unsigned int y = 0; y < height; ++y)
|
|
{
|
|
for (unsigned int x = 0; x < width; ++x)
|
|
{
|
|
pixels[0] = (pixels[0] * pixels[3]) / 0xFF;
|
|
pixels[1] = (pixels[1] * pixels[3]) / 0xFF;
|
|
pixels[2] = (pixels[2] * pixels[3]) / 0xFF;
|
|
pixels += 4;
|
|
}
|
|
}
|
|
|
|
glBindTexture(GL_TEXTURE_2D, surface->texture_id);
|
|
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, surface->pixels);
|
|
free(surface->pixels);
|
|
|
|
glBindTexture(GL_TEXTURE_2D, last_source_texture);
|
|
}
|
|
|
|
/////////////
|
|
// Drawing //
|
|
/////////////
|
|
|
|
void RenderBackend_Blit(RenderBackend_Surface *source_surface, const RenderBackend_Rect *rect, RenderBackend_Surface *destination_surface, long x, long y, bool alpha_blend)
|
|
{
|
|
if (source_surface == NULL || destination_surface == NULL)
|
|
return;
|
|
|
|
const RenderMode render_mode = (alpha_blend ? MODE_DRAW_SURFACE_WITH_TRANSPARENCY : MODE_DRAW_SURFACE);
|
|
|
|
// Flush vertex data if a context-change is needed
|
|
if (last_render_mode != render_mode || last_source_texture != source_surface->texture_id || last_destination_texture != destination_surface->texture_id)
|
|
{
|
|
FlushVertexBuffer();
|
|
|
|
last_render_mode = render_mode;
|
|
last_source_texture = source_surface->texture_id;
|
|
last_destination_texture = destination_surface->texture_id;
|
|
|
|
// Point our framebuffer to the destination texture
|
|
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, destination_surface->texture_id, 0);
|
|
glViewport(0, 0, destination_surface->width, destination_surface->height);
|
|
|
|
glUseProgram(program_texture);
|
|
|
|
if (alpha_blend)
|
|
glEnable(GL_BLEND);
|
|
else
|
|
glDisable(GL_BLEND);
|
|
|
|
// Enable texture coordinates, since this uses textures
|
|
glEnableVertexAttribArray(ATTRIBUTE_INPUT_TEXTURE_COORDINATES);
|
|
|
|
glBindTexture(GL_TEXTURE_2D, source_surface->texture_id);
|
|
}
|
|
|
|
// Add data to the vertex queue
|
|
const GLfloat texture_left = (GLfloat)rect->left / (GLfloat)source_surface->width;
|
|
const GLfloat texture_right = (GLfloat)rect->right / (GLfloat)source_surface->width;
|
|
const GLfloat texture_top = (GLfloat)rect->top / (GLfloat)source_surface->height;
|
|
const GLfloat texture_bottom = (GLfloat)rect->bottom / (GLfloat)source_surface->height;
|
|
|
|
const GLfloat vertex_left = (x * (2.0f / destination_surface->width)) - 1.0f;
|
|
const GLfloat vertex_right = ((x + (rect->right - rect->left)) * (2.0f / destination_surface->width)) - 1.0f;
|
|
const GLfloat vertex_top = (y * (2.0f / destination_surface->height)) - 1.0f;
|
|
const GLfloat vertex_bottom = ((y + (rect->bottom - rect->top)) * (2.0f / destination_surface->height)) - 1.0f;
|
|
|
|
VertexBufferSlot *vertex_buffer_slot = GetVertexBufferSlot(1);
|
|
|
|
if (vertex_buffer_slot != NULL)
|
|
{
|
|
vertex_buffer_slot->vertices[0][0].texture.x = texture_left;
|
|
vertex_buffer_slot->vertices[0][0].texture.y = texture_top;
|
|
vertex_buffer_slot->vertices[0][1].texture.x = texture_right;
|
|
vertex_buffer_slot->vertices[0][1].texture.y = texture_top;
|
|
vertex_buffer_slot->vertices[0][2].texture.x = texture_right;
|
|
vertex_buffer_slot->vertices[0][2].texture.y = texture_bottom;
|
|
|
|
vertex_buffer_slot->vertices[1][0].texture.x = texture_left;
|
|
vertex_buffer_slot->vertices[1][0].texture.y = texture_top;
|
|
vertex_buffer_slot->vertices[1][1].texture.x = texture_right;
|
|
vertex_buffer_slot->vertices[1][1].texture.y = texture_bottom;
|
|
vertex_buffer_slot->vertices[1][2].texture.x = texture_left;
|
|
vertex_buffer_slot->vertices[1][2].texture.y = texture_bottom;
|
|
|
|
vertex_buffer_slot->vertices[0][0].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[0][0].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[0][1].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[0][1].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[0][2].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[0][2].position.y = vertex_bottom;
|
|
|
|
vertex_buffer_slot->vertices[1][0].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[1][0].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[1][1].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[1][1].position.y = vertex_bottom;
|
|
vertex_buffer_slot->vertices[1][2].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[1][2].position.y = vertex_bottom;
|
|
}
|
|
}
|
|
|
|
void RenderBackend_ColourFill(RenderBackend_Surface *surface, const RenderBackend_Rect *rect, unsigned char red, unsigned char green, unsigned char blue, unsigned char alpha)
|
|
{
|
|
static unsigned char last_red;
|
|
static unsigned char last_green;
|
|
static unsigned char last_blue;
|
|
|
|
if (surface == NULL)
|
|
return;
|
|
|
|
// Flush vertex data if a context-change is needed
|
|
if (last_render_mode != MODE_COLOUR_FILL || last_destination_texture != surface->texture_id || last_red != red || last_green != green || last_blue != blue)
|
|
{
|
|
FlushVertexBuffer();
|
|
|
|
last_render_mode = MODE_COLOUR_FILL;
|
|
last_source_texture = 0;
|
|
last_destination_texture = surface->texture_id;
|
|
last_red = red;
|
|
last_green = green;
|
|
last_blue = blue;
|
|
|
|
// Point our framebuffer to the destination texture
|
|
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, surface->texture_id, 0);
|
|
glViewport(0, 0, surface->width, surface->height);
|
|
|
|
glUseProgram(program_colour_fill);
|
|
|
|
glDisable(GL_BLEND);
|
|
|
|
// Disable texture coordinate array, since this doesn't use textures
|
|
glDisableVertexAttribArray(ATTRIBUTE_INPUT_TEXTURE_COORDINATES);
|
|
|
|
glUniform4f(program_colour_fill_uniform_colour, red / 255.0f, green / 255.0f, blue / 255.0f, alpha / 255.0f);
|
|
}
|
|
|
|
// Add data to the vertex queue
|
|
const GLfloat vertex_left = (rect->left * (2.0f / surface->width)) - 1.0f;
|
|
const GLfloat vertex_right = (rect->right * (2.0f / surface->width)) - 1.0f;
|
|
const GLfloat vertex_top = (rect->top * (2.0f / surface->height)) - 1.0f;
|
|
const GLfloat vertex_bottom = (rect->bottom * (2.0f / surface->height)) - 1.0f;
|
|
|
|
VertexBufferSlot *vertex_buffer_slot = GetVertexBufferSlot(1);
|
|
|
|
if (vertex_buffer_slot != NULL)
|
|
{
|
|
vertex_buffer_slot->vertices[0][0].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[0][0].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[0][1].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[0][1].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[0][2].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[0][2].position.y = vertex_bottom;
|
|
|
|
vertex_buffer_slot->vertices[1][0].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[1][0].position.y = vertex_top;
|
|
vertex_buffer_slot->vertices[1][1].position.x = vertex_right;
|
|
vertex_buffer_slot->vertices[1][1].position.y = vertex_bottom;
|
|
vertex_buffer_slot->vertices[1][2].position.x = vertex_left;
|
|
vertex_buffer_slot->vertices[1][2].position.y = vertex_bottom;
|
|
}
|
|
}
|
|
|
|
//////////////////////
|
|
// Glyph management //
|
|
//////////////////////
|
|
|
|
RenderBackend_Glyph* RenderBackend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch)
|
|
{
|
|
RenderBackend_Glyph *glyph = (RenderBackend_Glyph*)malloc(sizeof(RenderBackend_Glyph));
|
|
|
|
if (glyph != NULL)
|
|
{
|
|
glyph->pitch = (width + 3) & ~3; // Round up to the nearest 4 (OpenGL needs this)
|
|
|
|
glyph->pixels = (unsigned char*)malloc(glyph->pitch * height);
|
|
|
|
if (glyph->pixels != NULL)
|
|
{
|
|
for (unsigned int y = 0; y < height; ++y)
|
|
{
|
|
const unsigned char *source_pointer = &pixels[y * pitch];
|
|
unsigned char *destination_pointer = &glyph->pixels[y * glyph->pitch];
|
|
memcpy(destination_pointer, source_pointer, width);
|
|
}
|
|
|
|
glyph->width = width;
|
|
glyph->height = height;
|
|
|
|
return glyph;
|
|
}
|
|
|
|
free(glyph);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void RenderBackend_UnloadGlyph(RenderBackend_Glyph *glyph)
|
|
{
|
|
if (glyph == NULL)
|
|
return;
|
|
|
|
free(glyph->pixels);
|
|
free(glyph);
|
|
}
|
|
|
|
void RenderBackend_PrepareToDrawGlyphs(RenderBackend_Surface *destination_surface, const unsigned char *colour_channels)
|
|
{
|
|
glyph_destination_surface = destination_surface;
|
|
|
|
memcpy(glyph_colour_channels, colour_channels, sizeof(glyph_colour_channels));
|
|
}
|
|
|
|
void RenderBackend_DrawGlyph(RenderBackend_Glyph *glyph, long x, long y)
|
|
{
|
|
spritebatch_push(&glyph_batcher, (SPRITEBATCH_U64)glyph, glyph->pitch, glyph->height, x, y, 1.0f, 1.0f, 0.0f, 0.0f, 0);
|
|
}
|
|
|
|
void RenderBackend_FlushGlyphs(void)
|
|
{
|
|
spritebatch_defrag(&glyph_batcher);
|
|
spritebatch_flush(&glyph_batcher);
|
|
}
|
|
|
|
///////////
|
|
// Misc. //
|
|
///////////
|
|
|
|
void RenderBackend_HandleRenderTargetLoss(void)
|
|
{
|
|
// No problem for us
|
|
}
|
|
|
|
void RenderBackend_HandleWindowResize(unsigned int width, unsigned int height)
|
|
{
|
|
actual_screen_width = width;
|
|
actual_screen_height = height;
|
|
}
|