4c024b540f
Goddammit 3.2 is so complex. The reason I want 3.2 is because I'm not convinced Legacy OpenGL will be well-supported in the future. 3.2 is about as far back as I can go without breaking forward-compatibility (it was the first version to introduce the Core Profile).
637 lines
20 KiB
C++
637 lines
20 KiB
C++
#include "../Rendering.h"
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#include <stddef.h>
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#include <stdlib.h>
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#include <GL/glew.h>
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#include "SDL.h"
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#include "../../WindowsWrapper.h"
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#include "../../Font.h"
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typedef struct Backend_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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} Backend_Surface;
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typedef struct Backend_Glyph
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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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} Backend_Glyph;
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static SDL_Window *window;
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static SDL_GLContext context;
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static GLuint program_texture;
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static GLuint program_texture_colour_key;
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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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static GLuint framebuffer_id;
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static GLuint vertex_buffer_id;
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static struct
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{
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GLfloat vertexes[4][2];
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GLfloat texture_coordinates[4][2];
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} vertex_buffer;
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static Backend_Surface framebuffer_surface;
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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.x, input_vertex_coordinates.y, 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.x, input_vertex_coordinates.y, 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 = texture2D(tex, texture_coordinates); \
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} \
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";
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static const GLchar *fragment_shader_texture_colour_key = " \
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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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vec4 colour = texture2D(tex, texture_coordinates); \
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\
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if (colour.xyz == vec3(0.0f, 0.0f, 0.0f)) \
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discard; \
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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_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 * vec4(1.0, 1.0, 1.0, texture2D(tex, texture_coordinates).r); \
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} \
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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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if (type == GL_DEBUG_TYPE_ERROR)
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printf("GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
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( type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "" ),
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type, severity, message);
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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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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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return 0;
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glAttachShader(program_id, vertex_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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return 0;
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glAttachShader(program_id, fragment_shader);
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glBindAttribLocation(program_id, 1, "input_vertex_coordinates");
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glBindAttribLocation(program_id, 2, "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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return 0;
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return program_id;
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}
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SDL_Window* Backend_CreateWindow(const char *title, int width, int height)
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{
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SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
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SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
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SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
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return SDL_CreateWindow(title, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, width, height, SDL_WINDOW_OPENGL);
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}
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BOOL Backend_Init(SDL_Window *p_window)
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{
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window = p_window;
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int window_width, window_height;
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SDL_GetWindowSize(window, &window_width, &window_height);
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context = SDL_GL_CreateContext(window);
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if (glewInit() != GLEW_OK)
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return FALSE;
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// Check if the platform supports OpenGL 3.2
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if (!GLEW_VERSION_3_2)
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return FALSE;
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// During init, enable debug output
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glEnable(GL_DEBUG_OUTPUT);
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glDebugMessageCallback(MessageCallback, 0);
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glEnable(GL_BLEND);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
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glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
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glClear(GL_COLOR_BUFFER_BIT);
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// Set up VAO
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GLuint vertex_array_id;
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glGenVertexArrays(1, &vertex_array_id);
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glBindVertexArray(vertex_array_id);
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// Set up VBO
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glGenBuffers(1, &vertex_buffer_id);
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glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_id);
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glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_buffer), NULL, GL_DYNAMIC_DRAW);
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// Set up IBO
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const GLuint indices[4] = {0, 1, 2, 3};
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GLuint indices_buffer_id;
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glGenBuffers(1, &indices_buffer_id);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indices_buffer_id);
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glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
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// Set up our shaders
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program_texture = CompileShader(vertex_shader_texture, fragment_shader_texture);
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program_texture_colour_key = CompileShader(vertex_shader_texture, fragment_shader_texture_colour_key);
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program_colour_fill = CompileShader(vertex_shader_plain, fragment_shader_colour_fill);
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program_glyph = CompileShader(vertex_shader_texture, fragment_shader_glyph);
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if (program_texture == 0 || program_texture_colour_key == 0 || program_colour_fill == 0 || program_glyph == 0)
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printf("Failed to compile shaders\n");
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// Get shader uniforms
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program_colour_fill_uniform_colour = glGetUniformLocation(program_colour_fill, "colour");
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program_glyph_uniform_colour = glGetUniformLocation(program_glyph, "colour");
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glEnableVertexAttribArray(1);
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glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, 0);
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glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(sizeof(GLfloat) * 4 * 2));
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// Set up framebuffer (used for surface-to-surface blitting)
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glGenFramebuffers(1, &framebuffer_id);
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glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);
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// Set up framebuffer screen texture (used for screen-to-surface blitting)
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glGenTextures(1, &framebuffer_surface.texture_id);
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glBindTexture(GL_TEXTURE_2D, framebuffer_surface.texture_id);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, window_width, window_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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framebuffer_surface.width = window_width;
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framebuffer_surface.height = window_height;
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return TRUE;
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}
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void Backend_Deinit(void)
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{
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glDeleteTextures(1, &framebuffer_surface.texture_id);
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glDeleteFramebuffers(1, &framebuffer_id);
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glDeleteProgram(program_glyph);
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glDeleteProgram(program_colour_fill);
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glDeleteProgram(program_texture_colour_key);
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glDeleteProgram(program_texture);
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SDL_GL_DeleteContext(context);
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}
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void Backend_DrawScreen(void)
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{
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glUseProgram(program_texture);
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// Enable texture coordinates, since this uses textures
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glEnableVertexAttribArray(2);
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// Target actual screen, and not our framebuffer
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glBindFramebuffer(GL_FRAMEBUFFER, 0);
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glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height);
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// Draw framebuffer to screen
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glBindTexture(GL_TEXTURE_2D, framebuffer_surface.texture_id);
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vertex_buffer.texture_coordinates[0][0] = 0.0f;
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vertex_buffer.texture_coordinates[0][1] = 1.0f;
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vertex_buffer.texture_coordinates[1][0] = 1.0f;
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vertex_buffer.texture_coordinates[1][1] = 1.0f;
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vertex_buffer.texture_coordinates[2][0] = 1.0f;
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vertex_buffer.texture_coordinates[2][1] = 0.0f;
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vertex_buffer.texture_coordinates[3][0] = 0.0f;
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vertex_buffer.texture_coordinates[3][1] = 0.0f;
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vertex_buffer.vertexes[0][0] = -1.0f;
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vertex_buffer.vertexes[0][1] = -1.0f;
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vertex_buffer.vertexes[1][0] = 1.0f;
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vertex_buffer.vertexes[1][1] = -1.0f;
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vertex_buffer.vertexes[2][0] = 1.0f;
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vertex_buffer.vertexes[2][1] = 1.0f;
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vertex_buffer.vertexes[3][0] = -1.0f;
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vertex_buffer.vertexes[3][1] = 1.0f;
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glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertex_buffer), &vertex_buffer);
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glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, NULL);
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SDL_GL_SwapWindow(window);
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// According to https://www.khronos.org/opengl/wiki/Common_Mistakes#Swap_Buffers
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// the buffer should always be cleared
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glClear(GL_COLOR_BUFFER_BIT);
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// Switch back to our framebuffer
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glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);
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}
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Backend_Surface* Backend_CreateSurface(unsigned int width, unsigned int height)
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{
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Backend_Surface *surface = (Backend_Surface*)malloc(sizeof(Backend_Surface));
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if (surface == NULL)
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return NULL;
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glGenTextures(1, &surface->texture_id);
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glBindTexture(GL_TEXTURE_2D, surface->texture_id);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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surface->width = width;
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surface->height = height;
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return surface;
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}
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void Backend_FreeSurface(Backend_Surface *surface)
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{
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if (surface == NULL)
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return;
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glDeleteTextures(1, &surface->texture_id);
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free(surface);
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}
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unsigned char* Backend_Lock(Backend_Surface *surface, unsigned int *pitch)
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{
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if (surface == NULL)
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return NULL;
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surface->pixels = (unsigned char*)malloc(surface->width * surface->height * 3);
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*pitch = surface->width * 3;
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return surface->pixels;
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}
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void Backend_Unlock(Backend_Surface *surface)
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{
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if (surface == NULL)
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return;
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glBindTexture(GL_TEXTURE_2D, surface->texture_id);
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glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, surface->width, surface->height, GL_RGB, GL_UNSIGNED_BYTE, surface->pixels);
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free(surface->pixels);
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}
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static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, Backend_Surface *destination_surface, long x, long y, BOOL colour_key)
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{
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if (rect->right - rect->left < 0 || rect->bottom - rect->top < 0)
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return;
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// Switch to colour-key shader if we have to
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glUseProgram(colour_key ? program_texture_colour_key : program_texture);
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// Enable texture coordinates, since this uses textures
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glEnableVertexAttribArray(2);
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glBindTexture(GL_TEXTURE_2D, source_surface->texture_id);
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const GLfloat texture_left = (GLfloat)rect->left / (GLfloat)source_surface->width;
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const GLfloat texture_right = (GLfloat)rect->right / (GLfloat)source_surface->width;
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const GLfloat texture_top = (GLfloat)rect->top / (GLfloat)source_surface->height;
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const GLfloat texture_bottom = (GLfloat)rect->bottom / (GLfloat)source_surface->height;
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const GLfloat vertex_left = (x * (2.0f / destination_surface->width)) - 1.0f;
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const GLfloat vertex_right = ((x + (rect->right - rect->left)) * (2.0f / destination_surface->width)) - 1.0f;
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const GLfloat vertex_top = (y * (2.0f / destination_surface->height)) - 1.0f;
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const GLfloat vertex_bottom = ((y + (rect->bottom - rect->top)) * (2.0f / destination_surface->height)) - 1.0f;
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vertex_buffer.texture_coordinates[0][0] = texture_left;
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vertex_buffer.texture_coordinates[0][1] = texture_top;
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vertex_buffer.texture_coordinates[1][0] = texture_right;
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vertex_buffer.texture_coordinates[1][1] = texture_top;
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vertex_buffer.texture_coordinates[2][0] = texture_right;
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vertex_buffer.texture_coordinates[2][1] = texture_bottom;
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vertex_buffer.texture_coordinates[3][0] = texture_left;
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vertex_buffer.texture_coordinates[3][1] = texture_bottom;
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vertex_buffer.vertexes[0][0] = vertex_left;
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vertex_buffer.vertexes[0][1] = vertex_top;
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vertex_buffer.vertexes[1][0] = vertex_right;
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vertex_buffer.vertexes[1][1] = vertex_top;
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vertex_buffer.vertexes[2][0] = vertex_right;
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vertex_buffer.vertexes[2][1] = vertex_bottom;
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vertex_buffer.vertexes[3][0] = vertex_left;
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vertex_buffer.vertexes[3][1] = vertex_bottom;
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glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertex_buffer), &vertex_buffer);
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glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, NULL);
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}
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void Backend_Blit(Backend_Surface *source_surface, const RECT *rect, Backend_Surface *destination_surface, long x, long y, BOOL colour_key)
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{
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if (source_surface == NULL || destination_surface == NULL)
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return;
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// Point our framebuffer to the destination texture
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glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, destination_surface->texture_id, 0);
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glViewport(0, 0, destination_surface->width, destination_surface->height);
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BlitCommon(source_surface, rect, destination_surface, x, y, colour_key);
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}
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void Backend_BlitToScreen(Backend_Surface *source_surface, const RECT *rect, long x, long y, BOOL colour_key)
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{
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if (source_surface == NULL)
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return;
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// Point our framebuffer to the screen texture
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glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0);
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glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height);
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BlitCommon(source_surface, rect, &framebuffer_surface, x, y, colour_key);
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}
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static void ColourFillCommon(Backend_Surface *surface, const RECT *rect, unsigned char red, unsigned char green, unsigned char blue)
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{
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if (rect->right - rect->left < 0 || rect->bottom - rect->top < 0)
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return;
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glUseProgram(program_colour_fill);
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// Disable texture coordinate array, since this doesn't use textures
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glDisableVertexAttribArray(2);
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glUniform4f(program_colour_fill_uniform_colour, red / 255.0f, green / 255.0f, blue / 255.0f, 1.0f);
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const GLfloat vertex_left = (rect->left * (2.0f / surface->width)) - 1.0f;
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const GLfloat vertex_right = (rect->right * (2.0f / surface->width)) - 1.0f;
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const GLfloat vertex_top = (rect->top * (2.0f / surface->height)) - 1.0f;
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const GLfloat vertex_bottom = (rect->bottom * (2.0f / surface->height)) - 1.0f;
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vertex_buffer.vertexes[0][0] = vertex_left;
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vertex_buffer.vertexes[0][1] = vertex_top;
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vertex_buffer.vertexes[1][0] = vertex_right;
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vertex_buffer.vertexes[1][1] = vertex_top;
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vertex_buffer.vertexes[2][0] = vertex_right;
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vertex_buffer.vertexes[2][1] = vertex_bottom;
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vertex_buffer.vertexes[3][0] = vertex_left;
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vertex_buffer.vertexes[3][1] = vertex_bottom;
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glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertex_buffer), &vertex_buffer);
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glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, NULL);
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}
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void Backend_ColourFill(Backend_Surface *surface, const RECT *rect, unsigned char red, unsigned char green, unsigned char blue)
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{
|
|
if (surface == NULL)
|
|
return;
|
|
|
|
// 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);
|
|
|
|
ColourFillCommon(surface, rect, red, green, blue);
|
|
}
|
|
|
|
void Backend_ColourFillToScreen(const RECT *rect, unsigned char red, unsigned char green, unsigned char blue)
|
|
{
|
|
// Point our framebuffer to the screen texture
|
|
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0);
|
|
glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height);
|
|
|
|
ColourFillCommon(&framebuffer_surface, rect, red, green, blue);
|
|
}
|
|
|
|
void Backend_ScreenToSurface(Backend_Surface *surface, const RECT *rect)
|
|
{
|
|
if (surface == NULL)
|
|
return;
|
|
|
|
// 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);
|
|
|
|
BlitCommon(&framebuffer_surface, rect, surface, rect->left, rect->top, FALSE);
|
|
}
|
|
|
|
BOOL Backend_SupportsSubpixelGlyph(void)
|
|
{
|
|
return FALSE; // Per-component alpha is available as an extension, but I haven't looked into it yet
|
|
}
|
|
|
|
Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned short total_greys, unsigned char pixel_mode)
|
|
{
|
|
Backend_Glyph *glyph = (Backend_Glyph*)malloc(sizeof(Backend_Glyph));
|
|
|
|
if (glyph == NULL)
|
|
return NULL;
|
|
|
|
const int destination_pitch = (width + 3) & ~3; // Round up to the nearest 4 (OpenGL needs this)
|
|
|
|
unsigned char *buffer = (unsigned char*)malloc(destination_pitch * height);
|
|
|
|
if (buffer == NULL)
|
|
{
|
|
free(glyph);
|
|
return NULL;
|
|
}
|
|
|
|
switch (pixel_mode)
|
|
{
|
|
// FONT_PIXEL_MODE_LCD is unsupported
|
|
|
|
case FONT_PIXEL_MODE_GRAY:
|
|
for (unsigned int y = 0; y < height; ++y)
|
|
{
|
|
const unsigned char *source_pointer = pixels + y * pitch;
|
|
unsigned char *destination_pointer = buffer + y * destination_pitch;
|
|
|
|
for (unsigned int x = 0; x < width; ++x)
|
|
{
|
|
*destination_pointer++ = (unsigned char)(pow((double)*source_pointer++ / (total_greys - 1), 1.0 / 1.8) * 255.0);
|
|
}
|
|
}
|
|
|
|
break;
|
|
|
|
case FONT_PIXEL_MODE_MONO:
|
|
for (unsigned int y = 0; y < height; ++y)
|
|
{
|
|
const unsigned char *source_pointer = pixels + y * pitch;
|
|
unsigned char *destination_pointer = buffer + y * destination_pitch;
|
|
|
|
for (unsigned int x = 0; x < width; ++x)
|
|
{
|
|
*destination_pointer++ = *source_pointer++ ? 0xFF : 0;
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
glGenTextures(1, &glyph->texture_id);
|
|
glBindTexture(GL_TEXTURE_2D, glyph->texture_id);
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, buffer);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
|
|
|
|
glyph->width = width;
|
|
glyph->height = height;
|
|
|
|
free(buffer);
|
|
|
|
return glyph;
|
|
}
|
|
|
|
void Backend_UnloadGlyph(Backend_Glyph *glyph)
|
|
{
|
|
if (glyph == NULL)
|
|
return;
|
|
|
|
glDeleteTextures(1, &glyph->texture_id);
|
|
free(glyph);
|
|
}
|
|
|
|
static void DrawGlyphCommon(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)
|
|
{
|
|
glUseProgram(program_glyph);
|
|
|
|
// Enable texture coordinates, since this uses textures
|
|
glEnableVertexAttribArray(2);
|
|
|
|
glBindTexture(GL_TEXTURE_2D, glyph->texture_id);
|
|
|
|
const GLfloat vertex_left = (x * (2.0f / surface->width)) - 1.0f;
|
|
const GLfloat vertex_right = ((x + glyph->width) * (2.0f / surface->width)) - 1.0f;
|
|
const GLfloat vertex_top = (y * (2.0f / surface->height)) - 1.0f;
|
|
const GLfloat vertex_bottom = ((y + glyph->height) * (2.0f / surface->height)) - 1.0f;
|
|
|
|
glUniform4f(program_glyph_uniform_colour, colours[0] / 255.0f, colours[1] / 255.0f, colours[2] / 255.0f, 1.0f);
|
|
|
|
vertex_buffer.texture_coordinates[0][0] = 0.0f;
|
|
vertex_buffer.texture_coordinates[0][1] = 0.0f;
|
|
vertex_buffer.texture_coordinates[1][0] = 1.0f;
|
|
vertex_buffer.texture_coordinates[1][1] = 0.0f;
|
|
vertex_buffer.texture_coordinates[2][0] = 1.0f;
|
|
vertex_buffer.texture_coordinates[2][1] = 1.0f;
|
|
vertex_buffer.texture_coordinates[3][0] = 0.0f;
|
|
vertex_buffer.texture_coordinates[3][1] = 1.0f;
|
|
|
|
vertex_buffer.vertexes[0][0] = vertex_left;
|
|
vertex_buffer.vertexes[0][1] = vertex_top;
|
|
vertex_buffer.vertexes[1][0] = vertex_right;
|
|
vertex_buffer.vertexes[1][1] = vertex_top;
|
|
vertex_buffer.vertexes[2][0] = vertex_right;
|
|
vertex_buffer.vertexes[2][1] = vertex_bottom;
|
|
vertex_buffer.vertexes[3][0] = vertex_left;
|
|
vertex_buffer.vertexes[3][1] = vertex_bottom;
|
|
|
|
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertex_buffer), &vertex_buffer);
|
|
glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, NULL);
|
|
}
|
|
|
|
void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)
|
|
{
|
|
if (glyph == NULL || surface == NULL)
|
|
return;
|
|
|
|
// 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);
|
|
|
|
DrawGlyphCommon(surface, glyph, x, y, colours);
|
|
}
|
|
|
|
void Backend_DrawGlyphToScreen(Backend_Glyph *glyph, long x, long y, const unsigned char *colours)
|
|
{
|
|
if (glyph == NULL)
|
|
return;
|
|
|
|
// Point our framebuffer to the screen texture
|
|
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0);
|
|
glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height);
|
|
|
|
DrawGlyphCommon(&framebuffer_surface, glyph, x, y, colours);
|
|
}
|
|
|
|
void Backend_HandleDeviceLoss(void)
|
|
{
|
|
// No problem for us
|
|
}
|
|
|
|
void Backend_HandleWindowResize(void)
|
|
{
|
|
// No problem for us
|
|
}
|