ref: 3db2a5e65833c3da922f32ce5cc1396349fdbf1f
dir: /src/render_gl.c/
// macOS
#if defined(__APPLE__) && defined(__MACH__)
#include <OpenGL/gl.h>
#include <OpenGL/glext.h>
void glCreateTextures(GLuint ignored, GLsizei n, GLuint *name) {
glGenTextures(1, name);
}
#define glGenVertexArrays glGenVertexArraysAPPLE
#define glBindVertexArray glBindVertexArrayAPPLE
#define glDeleteVertexArrays glDeleteVertexArraysAPPLE
// Linux
#elif defined(__unix__)
#include <GL/glew.h>
#ifdef __EMSCRIPTEN__
void glCreateTextures(GLuint ignored, GLsizei n, GLuint *name) {
glGenTextures(1, name);
}
#endif
// WINDOWS
#else
#include <windows.h>
#define GL3_PROTOTYPES 1
#include <glew.h>
#pragma comment(lib, "glew32.lib")
#include <gl/GL.h>
#pragma comment(lib, "opengl32.lib")
#endif
#include "libs/stb_image_write.h"
#include "render.h"
#include "mem.h"
#include "utils.h"
#define NEAR_PLANE 16.0
#define FAR_PLANE 262144.0
#define ATLAS_SIZE 64
#define ATLAS_GRID 32
#define ATLAS_BORDER 16
#define RENDER_TRIS_BUFFER_CAPACITY 2048
#define TEXTURES_MAX 1024
// WebGL (GLES) needs the `precision` to be set, OpenGL 2.something
// doesn't like that...
#ifdef __EMSCRIPTEN__
#define SHADER_SOURCE(...) "precision highp float;" #__VA_ARGS__
#else
#define SHADER_SOURCE(...) #__VA_ARGS__
#endif
typedef struct {
vec2i_t offset;
vec2i_t size;
} render_texture_t;
uint16_t RENDER_NO_TEXTURE;
static GLuint u_color;
static GLuint u_view;
static GLuint u_model;
static GLuint u_projection;
static GLuint u_screen;
static GLuint u_camera_pos;
static GLuint u_fade;
static GLuint a_pos;
static GLuint a_uv;
static GLuint a_color;
static GLuint vbo;
static tris_t tris_buffer[RENDER_TRIS_BUFFER_CAPACITY];
static uint32_t tris_len = 0;
static vec2i_t screen_size;
static uint32_t atlas_map[ATLAS_SIZE] = {0};
static GLuint atlas_texture = 0;
static render_blend_mode_t blend_mode = RENDER_BLEND_NORMAL;
static mat4_t projection_mat_2d = mat4_identity();
static mat4_t projection_mat_3d = mat4_identity();
static mat4_t sprite_mat = mat4_identity();
static mat4_t view_mat = mat4_identity();
static render_texture_t textures[TEXTURES_MAX];
static uint32_t textures_len = 0;
static bool texture_mipmap_is_dirty = false;
static const char * const VERTEX_SHADER = SHADER_SOURCE(
attribute vec3 pos;
attribute vec2 uv;
attribute vec4 color;
varying vec4 v_color;
varying vec2 v_uv;
uniform mat4 view;
uniform mat4 model;
uniform mat4 projection;
uniform vec2 screen;
uniform vec3 camera_pos;
uniform vec2 fade;
void main() {
gl_Position = projection * view * model * vec4(pos, 1.0);
gl_Position.xy += screen.xy * gl_Position.w;
v_color = color;
v_color.a *= smoothstep(
fade.y, fade.x, // fadeout far, near
length(vec4(camera_pos, 1.0) - model * vec4(pos, 1.0))
);
v_uv = uv;
v_uv = uv / 2048.0; // ATLAS_GRID * ATLAS_SIZE
}
);
static const char * const FRAGMENT_SHADER_YCRCB = SHADER_SOURCE(
varying vec4 v_color;
varying vec2 v_uv;
uniform sampler2D texture;
void main() {
vec4 tex_color = texture2D(texture, v_uv);
vec4 color = tex_color * v_color;
if (color.a == 0.0) {
discard;
}
color.rgb = color.rgb * 2.0;
gl_FragColor = color;
}
);
#define render_bind_va_f(index, container, member, start) \
glVertexAttribPointer( \
index, member_size(container, member)/sizeof(float), GL_FLOAT, false, \
sizeof(container), \
(GLvoid*)(offsetof(container, member) + start) \
)
#define render_bind_va_color(index, container, member, start) \
glVertexAttribPointer( \
index, 4, GL_UNSIGNED_BYTE, true, \
sizeof(container), \
(GLvoid*)(offsetof(container, member) + start) \
)
static void render_flush();
static GLuint compile_shader(GLenum type, const char *source);
static GLuint compile_shader(GLenum type, const char *source) {
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &source, NULL);
glCompileShader(shader);
GLint success;
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success) {
int log_written;
char log[256];
glGetShaderInfoLog(shader, 256, &log_written, log);
die("Error compiling shader: %s\n", log);
}
return shader;
}
// static void gl_message_callback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam) {
// puts(message);
// }
void render_init(vec2i_t size) {
#if defined(__APPLE__) && defined(__MACH__)
// OSX
// (nothing to do here)
#else
// Windows, Linux
glewExperimental = GL_TRUE;
glewInit();
#endif
// glEnable(GL_DEBUG_OUTPUT);
// glDebugMessageCallback(gl_message_callback, NULL);
// glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, GL_TRUE);
// Atlas Texture
glCreateTextures(GL_TEXTURE_2D, 1, &atlas_texture);
glBindTexture(GL_TEXTURE_2D, atlas_texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, RENDER_USE_MIPMAPS ? GL_LINEAR_MIPMAP_LINEAR : 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);
float anisotropy = 0;
glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &anisotropy);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, anisotropy);
uint32_t tw = ATLAS_SIZE * ATLAS_GRID;
uint32_t th = ATLAS_SIZE * ATLAS_GRID;
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tw, th, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
printf("atlas texture %5d\n", atlas_texture);
// Shaders
GLuint fragment_shader = compile_shader(GL_FRAGMENT_SHADER, FRAGMENT_SHADER_YCRCB);
GLuint vertex_shader = compile_shader(GL_VERTEX_SHADER, VERTEX_SHADER);
GLuint shader_program = glCreateProgram();
glAttachShader(shader_program, vertex_shader);
glAttachShader(shader_program, fragment_shader);
glLinkProgram(shader_program);
glUseProgram(shader_program);
u_color = glGetUniformLocation(shader_program, "color");
u_view = glGetUniformLocation(shader_program, "view");
u_model = glGetUniformLocation(shader_program, "model");
u_projection = glGetUniformLocation(shader_program, "projection");
u_screen = glGetUniformLocation(shader_program, "screen");
u_camera_pos = glGetUniformLocation(shader_program, "camera_pos");
u_fade = glGetUniformLocation(shader_program, "fade");
a_pos = glGetAttribLocation(shader_program, "pos");
a_uv = glGetAttribLocation(shader_program, "uv");
a_color = glGetAttribLocation(shader_program, "color");
// Tris buffer
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
GLuint va;
glGenVertexArrays(1, &va);
glBindVertexArray(va);
// Defaults
glEnableVertexAttribArray(a_pos);
glEnableVertexAttribArray(a_uv);
glEnableVertexAttribArray(a_color);
render_bind_va_f(a_pos, vertex_t, pos, 0);
render_bind_va_f(a_uv, vertex_t, uv, 0);
render_bind_va_color(a_color, vertex_t, color, 0);
render_resize(size);
render_set_view(vec3(0, 0, 0), vec3(0, 0, 0));
render_set_model_mat(&mat4_identity());
glEnable(GL_CULL_FACE);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// Create white texture
rgba_t white_pixels[4] = {
rgba(128,128,128,255), rgba(128,128,128,255),
rgba(128,128,128,255), rgba(128,128,128,255)
};
RENDER_NO_TEXTURE = render_texture_create(2, 2, white_pixels);
}
void render_cleanup() {
// TODO
}
static void render_setup_2d_projection_mat() {
float near = -1;
float far = 1;
float left = 0;
float right = screen_size.x;
float bottom = screen_size.y;
float top = 0;
float lr = 1 / (left - right);
float bt = 1 / (bottom - top);
float nf = 1 / (near - far);
projection_mat_2d = mat4(
-2 * lr, 0, 0, 0,
0, -2 * bt, 0, 0,
0, 0, 2 * nf, 0,
(left + right) * lr, (top + bottom) * bt, (far + near) * nf, 1
);
}
static void render_setup_3d_projection_mat() {
// wipeout has a horizontal fov of 90deg, but we want the fov to be fixed
// for the vertical axis, so that widescreen displays just have a wider
// view. For the original 4/3 aspect ratio this equates to a vertial fov
// of 73.75deg.
float aspect = (float)screen_size.x / (float)screen_size.y;
float fov = (73.75 / 180.0) * 3.14159265358;
float f = 1.0 / tan(fov / 2);
float nf = 1.0 / (NEAR_PLANE - FAR_PLANE);
projection_mat_3d = mat4(
f / aspect, 0, 0, 0,
0, f, 0, 0,
0, 0, (FAR_PLANE + NEAR_PLANE) * nf, -1,
0, 0, 2 * FAR_PLANE * NEAR_PLANE * nf, 0
);
}
void render_resize(vec2i_t size) {
glViewport(0, 0, size.x, size.y);
screen_size = size;
render_setup_2d_projection_mat();
render_setup_3d_projection_mat();
}
vec2i_t render_size() {
return screen_size;
}
void render_frame_prepare() {
glUniform2f(u_screen, 0, 0);
glEnable(GL_DEPTH_TEST);
glDepthMask(true);
glDisable(GL_POLYGON_OFFSET_FILL);
glClearColor(0, 0, 0, 1);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
}
void render_frame_end() {
render_flush();
}
void render_flush() {
if (tris_len == 0) {
return;
}
if (texture_mipmap_is_dirty) {
glGenerateMipmap(GL_TEXTURE_2D);
texture_mipmap_is_dirty = false;
}
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(tris_t) * tris_len, tris_buffer, GL_DYNAMIC_DRAW);
glDrawArrays(GL_TRIANGLES, 0, tris_len * 3);
tris_len = 0;
}
void render_set_view(vec3_t pos, vec3_t angles) {
render_flush();
render_set_depth_write(true);
render_set_depth_test(true);
view_mat = mat4_identity();
mat4_set_translation(&view_mat, vec3(0, 0, 0));
mat4_set_roll_pitch_yaw(&view_mat, vec3(angles.x, -angles.y + M_PI, angles.z + M_PI));
mat4_translate(&view_mat, vec3_inv(pos));
mat4_set_yaw_pitch_roll(&sprite_mat, vec3(-angles.x, angles.y - M_PI, 0));
render_set_model_mat(&mat4_identity());
render_flush();
glUniformMatrix4fv(u_view, 1, false, view_mat.m);
glUniformMatrix4fv(u_projection, 1, false, projection_mat_3d.m);
glUniform3f(u_camera_pos, pos.x, pos.y, pos.z);
glUniform2f(u_fade, RENDER_FADEOUT_NEAR, RENDER_FADEOUT_FAR);
}
void render_set_view_2d() {
render_flush();
render_set_depth_test(false);
render_set_depth_write(false);
render_set_model_mat(&mat4_identity());
glUniform3f(u_camera_pos, 0, 0, 0);
glUniformMatrix4fv(u_view, 1, false, mat4_identity().m);
glUniformMatrix4fv(u_projection, 1, false, projection_mat_2d.m);
}
void render_set_model_mat(mat4_t *m) {
render_flush();
glUniformMatrix4fv(u_model, 1, false, m->m);
}
void render_set_depth_write(bool enabled) {
render_flush();
glDepthMask(enabled);
}
void render_set_depth_test(bool enabled) {
render_flush();
if (enabled) {
glEnable(GL_DEPTH_TEST);
}
else {
glDisable(GL_DEPTH_TEST);
}
}
void render_set_depth_offset(float offset) {
render_flush();
if (offset == 0) {
glDisable(GL_POLYGON_OFFSET_FILL);
return;
}
glEnable(GL_POLYGON_OFFSET_FILL);
glPolygonOffset(offset, 1.0);
}
void render_set_screen_position(vec2_t pos) {
render_flush();
glUniform2f(u_screen, pos.x, -pos.y);
}
void render_set_blend_mode(render_blend_mode_t new_mode) {
if (new_mode == blend_mode) {
return;
}
render_flush();
blend_mode = new_mode;
if (blend_mode == RENDER_BLEND_NORMAL) {
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
else if (blend_mode == RENDER_BLEND_LIGHTER) {
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
}
}
void render_set_cull_backface(bool enabled) {
render_flush();
if (enabled) {
glEnable(GL_CULL_FACE);
}
else {
glDisable(GL_CULL_FACE);
}
}
vec3_t render_transform(vec3_t pos) {
return vec3_transform(vec3_transform(pos, &view_mat), &projection_mat_3d);
}
void render_push_tris(tris_t tris, uint16_t texture_index) {
error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);
if (tris_len >= RENDER_TRIS_BUFFER_CAPACITY) {
render_flush();
}
render_texture_t *t = &textures[texture_index];
for (int i = 0; i < 3; i++) {
tris.vertices[i].uv.x += t->offset.x;
tris.vertices[i].uv.y += t->offset.y;
}
tris_buffer[tris_len++] = tris;
}
void render_push_sprite(vec3_t pos, vec2i_t size, rgba_t color, uint16_t texture_index) {
error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);
vec3_t p1 = vec3_add(pos, vec3_transform(vec3(-size.x * 0.5, -size.y * 0.5, 0), &sprite_mat));
vec3_t p2 = vec3_add(pos, vec3_transform(vec3( size.x * 0.5, -size.y * 0.5, 0), &sprite_mat));
vec3_t p3 = vec3_add(pos, vec3_transform(vec3(-size.x * 0.5, size.y * 0.5, 0), &sprite_mat));
vec3_t p4 = vec3_add(pos, vec3_transform(vec3( size.x * 0.5, size.y * 0.5, 0), &sprite_mat));
render_texture_t *t = &textures[texture_index];
render_push_tris((tris_t){
.vertices = {
{
.pos = p1,
.uv = {0, 0},
.color = color
},
{
.pos = p2,
.uv = {0 + t->size.x ,0},
.color = color
},
{
.pos = p3,
.uv = {0, 0 + t->size.y},
.color = color
},
}
}, texture_index);
render_push_tris((tris_t){
.vertices = {
{
.pos = p3,
.uv = {0, 0 + t->size.y},
.color = color
},
{
.pos = p2,
.uv = {0 + t->size.x, 0},
.color = color
},
{
.pos = p4,
.uv = {0 + t->size.x, 0 + t->size.y},
.color = color
},
}
}, texture_index);
}
void render_push_2d(vec2i_t pos, vec2i_t size, rgba_t color, uint16_t texture_index) {
render_push_2d_tile(pos, vec2i(0, 0), render_texture_size(texture_index), size, color, texture_index);
}
void render_push_2d_tile(vec2i_t pos, vec2i_t uv_offset, vec2i_t uv_size, vec2i_t size, rgba_t color, uint16_t texture_index) {
error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);
render_push_tris((tris_t){
.vertices = {
{
.pos = {pos.x, pos.y + size.y, 0},
.uv = {uv_offset.x , uv_offset.y + uv_size.y},
.color = color
},
{
.pos = {pos.x + size.x, pos.y, 0},
.uv = {uv_offset.x + uv_size.x, uv_offset.y},
.color = color
},
{
.pos = {pos.x, pos.y, 0},
.uv = {uv_offset.x , uv_offset.y},
.color = color
},
}
}, texture_index);
render_push_tris((tris_t){
.vertices = {
{
.pos = {pos.x + size.x, pos.y + size.y, 0},
.uv = {uv_offset.x + uv_size.x, uv_offset.y + uv_size.y},
.color = color
},
{
.pos = {pos.x + size.x, pos.y, 0},
.uv = {uv_offset.x + uv_size.x, uv_offset.y},
.color = color
},
{
.pos = {pos.x, pos.y + size.y, 0},
.uv = {uv_offset.x , uv_offset.y + uv_size.y},
.color = color
},
}
}, texture_index);
}
uint16_t render_texture_create(uint32_t tw, uint32_t th, rgba_t *pixels) {
error_if(textures_len >= TEXTURES_MAX, "TEXTURES_MAX reached");
uint32_t bw = tw + ATLAS_BORDER * 2;
uint32_t bh = th + ATLAS_BORDER * 2;
// Find a position in the atlas for this texture (with added border)
uint32_t grid_width = (bw + ATLAS_GRID - 1) / ATLAS_GRID;
uint32_t grid_height = (bh + ATLAS_GRID - 1) / ATLAS_GRID;
uint32_t grid_x = 0;
uint32_t grid_y = ATLAS_SIZE - grid_height + 1;
for (uint32_t cx = 0; cx < ATLAS_SIZE - grid_width; cx++) {
if (atlas_map[cx] >= grid_y) {
continue;
}
uint32_t cy = atlas_map[cx];
bool is_best = true;
for (uint32_t bx = cx; bx < cx + grid_width; bx++) {
if (atlas_map[bx] >= grid_y) {
is_best = false;
cx = bx;
break;
}
if (atlas_map[bx] > cy) {
cy = atlas_map[bx];
}
}
if (is_best) {
grid_y = cy;
grid_x = cx;
}
}
error_if(grid_y + grid_height > ATLAS_SIZE, "Render atlas ran out of space");
for (uint32_t cx = grid_x; cx < grid_x + grid_width; cx++) {
atlas_map[cx] = grid_y + grid_height;
}
// Add the border pixels for this texture
rgba_t *pb = mem_temp_alloc(sizeof(rgba_t) * bw * bh);
if (tw && th) {
// Top border
for (int32_t y = 0; y < ATLAS_BORDER; y++) {
memcpy(pb + bw * y + ATLAS_BORDER, pixels, tw * sizeof(rgba_t));
}
// Bottom border
for (int32_t y = 0; y < ATLAS_BORDER; y++) {
memcpy(pb + bw * (bh - ATLAS_BORDER + y) + ATLAS_BORDER, pixels + tw * (th-1), tw * sizeof(rgba_t));
}
// Left border
for (int32_t y = 0; y < bh; y++) {
for (int32_t x = 0; x < ATLAS_BORDER; x++) {
pb[y * bw + x] = pixels[clamp(y-ATLAS_BORDER, 0, th-1) * tw];
}
}
// Right border
for (int32_t y = 0; y < bh; y++) {
for (int32_t x = 0; x < ATLAS_BORDER; x++) {
pb[y * bw + x + bw - ATLAS_BORDER] = pixels[tw - 1 + clamp(y-ATLAS_BORDER, 0, th-1) * tw];
}
}
// Texture
for (int32_t y = 0; y < th; y++) {
memcpy(pb + bw * (y + ATLAS_BORDER) + ATLAS_BORDER, pixels + tw * y, tw * sizeof(rgba_t));
}
}
uint32_t x = grid_x * ATLAS_GRID;
uint32_t y = grid_y * ATLAS_GRID;
glBindTexture(GL_TEXTURE_2D, atlas_texture);
glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, bw, bh, GL_RGBA, GL_UNSIGNED_BYTE, pb);
mem_temp_free(pb);
texture_mipmap_is_dirty = RENDER_USE_MIPMAPS;
uint16_t texture_index = textures_len;
textures_len++;
textures[texture_index] = (render_texture_t){ {x + ATLAS_BORDER, y + ATLAS_BORDER}, {tw, th} };
printf("inserted atlas texture (%3dx%3d) at (%3d,%3d)\n", tw, th, grid_x, grid_y);
return texture_index;
}
vec2i_t render_texture_size(uint16_t texture_index) {
error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);
return textures[texture_index].size;
}
void render_texture_replace_pixels(int16_t texture_index, rgba_t *pixels) {
error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);
render_texture_t *t = &textures[texture_index];
glBindTexture(GL_TEXTURE_2D, atlas_texture);
glTexSubImage2D(GL_TEXTURE_2D, 0, t->offset.x, t->offset.y, t->size.x, t->size.y, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
}
uint16_t render_textures_len() {
return textures_len;
}
void render_textures_reset(uint16_t len) {
error_if(len > textures_len, "Invalid texture reset len %d >= %d", len, textures_len);
render_flush();
textures_len = len;
clear(atlas_map);
// Clear completely and recreate the default white texture
if (len == 0) {
rgba_t white_pixels[4] = {
rgba(128,128,128,255), rgba(128,128,128,255),
rgba(128,128,128,255), rgba(128,128,128,255)
};
RENDER_NO_TEXTURE = render_texture_create(2, 2, white_pixels);
return;
}
// Replay all texture grid insertions up to the reset len
for (int i = 0; i < textures_len; i++) {
uint32_t grid_x = (textures[i].offset.x - ATLAS_BORDER) / ATLAS_GRID;
uint32_t grid_y = (textures[i].offset.y - ATLAS_BORDER) / ATLAS_GRID;
uint32_t grid_width = (textures[i].size.x + ATLAS_BORDER * 2 + ATLAS_GRID - 1) / ATLAS_GRID;
uint32_t grid_height = (textures[i].size.y + ATLAS_BORDER * 2 + ATLAS_GRID - 1) / ATLAS_GRID;
for (uint32_t cx = grid_x; cx < grid_x + grid_width; cx++) {
atlas_map[cx] = grid_y + grid_height;
}
}
}
void render_textures_dump(const char *path) {
int width = ATLAS_SIZE * ATLAS_GRID;
int height = ATLAS_SIZE * ATLAS_GRID;
rgba_t *pixels = malloc(sizeof(rgba_t) * width * height);
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
stbi_write_png(path, width, height, 4, pixels, 0);
free(pixels);
}