Files
forge-steel/src/shaders.c
T
2025-09-18 13:42:21 +02:00

298 lines
8.7 KiB
C

#include <glad/gl.h>
#include <linmath.h>
#include <stddef.h>
#include "config.h"
#include "constants.h"
#include "logs.h"
#include "types.h"
static bool compile_shader(GLuint shader_id, char *name, char *source_code) {
GLint status_params;
char log[1024];
log_info("Compiling '%s'...", name);
// update shader source code
glShaderSource(shader_id, 1, (const GLchar **)&source_code, NULL);
// compile shader
glCompileShader(shader_id);
// get compilation status
glGetShaderiv(shader_id, GL_COMPILE_STATUS, &status_params);
glGetShaderInfoLog(shader_id, 1024, NULL, (GLchar *)&log);
if (status_params == GL_FALSE) {
log_error("Failed to compile\n%s", log);
} else {
log_success("Compilation successful");
}
return status_params == GL_TRUE;
}
static void init_textures(ShaderProgram *program, Context context) {
unsigned int i;
glGenTextures(TEX_COUNT, program->textures);
for (i = 0; i < TEX_COUNT; i++) {
// selects which texture unit subsequent texture state calls will affect
glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(GL_TEXTURE_2D, program->textures[i]);
// define texture image as empty
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, context.width, context.height, 0,
GL_RGB, GL_UNSIGNED_BYTE, 0);
// setup mipmap context
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
log_success("Texture %d initialized", i);
}
}
static void init_framebuffers(ShaderProgram *program) {
unsigned int i, j;
glGenFramebuffers(FRAG_COUNT, program->frame_buffers);
for (i = 0; i < FRAG_COUNT; i++) {
glBindFramebuffer(GL_FRAMEBUFFER, program->frame_buffers[i]);
for (j = 0; j < TEX_COUNT; j++) {
// attaches a selected mipmap level or image of a texture object as one of
// the logical buffers of the framebuffer object
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + j,
GL_TEXTURE_2D, program->textures[j], 0);
}
// check framebuffer status
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
log_error("Framebuffer %d is KO: %x", i + 1,
glCheckFramebufferStatus(GL_FRAMEBUFFER));
program->error = true;
return;
}
log_success("Framebuffer %d initialized", i);
}
return;
}
static void init_vertices(ShaderProgram *program) {
// create vertex buffer and setup vertices
glGenBuffers(1, &program->vertex_buffer);
glBindBuffer(GL_ARRAY_BUFFER, program->vertex_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// create vertex array
glGenVertexArrays(1, &program->vertex_array);
glBindVertexArray(program->vertex_array);
}
static void init_shaders(ShaderProgram *program, File *fragment_shaders) {
unsigned int i;
// compile vertex shader
program->vertex_shader = glCreateShader(GL_VERTEX_SHADER);
program->error |= !compile_shader(
program->vertex_shader, "internal vertex shader", vertex_shader_text);
// compile output fragment shader
program->output_fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
program->error |=
!compile_shader(program->output_fragment_shader,
"internal fragment shader", output_fragment_shader_text);
// compile fragment shaders
for (i = 0; i < FRAG_COUNT; i++) {
program->fragment_shaders[i] = glCreateShader(GL_FRAGMENT_SHADER);
program->error |=
!compile_shader(program->fragment_shaders[i], fragment_shaders[i].path,
fragment_shaders[i].content);
if (program->error) {
return;
}
}
}
static void init_single_program(ShaderProgram *program, unsigned int i,
bool output) {
unsigned int j;
char name[32];
program->programs[i] = glCreateProgram();
glAttachShader(program->programs[i], program->vertex_shader);
if (output) {
glAttachShader(program->programs[i], program->output_fragment_shader);
} else {
glAttachShader(program->programs[i], program->fragment_shaders[i]);
}
glLinkProgram(program->programs[i]);
// create uniforms pointers
if (!output) {
program->itime_locations[i] =
glGetUniformLocation(program->programs[i], "iTime");
program->itempo_locations[i] =
glGetUniformLocation(program->programs[i], "iTempo");
program->ifps_locations[i] =
glGetUniformLocation(program->programs[i], "iFPS");
program->ires_locations[i] =
glGetUniformLocation(program->programs[i], "iResolution");
for (j = 0; j < SUB_COUNT; j++) {
sprintf(name, "src_%d", j);
program->sub_src_indexes[i][j] =
glGetSubroutineIndex(program->programs[i], GL_FRAGMENT_SHADER, name);
sprintf(name, "fx_%d", j);
program->sub_fx_indexes[i][j] =
glGetSubroutineIndex(program->programs[i], GL_FRAGMENT_SHADER, name);
if (j < 2) {
sprintf(name, "mix_%d", j);
program->sub_mix_indexes[i][j] = glGetSubroutineIndex(
program->programs[i], GL_FRAGMENT_SHADER, name);
}
}
}
// create frameX uniforms pointer
for (j = 0; j < TEX_COUNT; j++) {
sprintf(name, "frame%d", j);
program->frames_locations[i][j] =
glGetUniformLocation(program->programs[i], name);
}
// create attribute pointer
program->vpos_locations[i] =
glGetAttribLocation(program->programs[i], "vPos");
// enable attribute pointer
glEnableVertexAttribArray(program->vpos_locations[i]);
// specify the location and data format of the array of generic vertex
// attributes to use when rendering
glVertexAttribPointer(program->vpos_locations[i], 2, GL_FLOAT, GL_FALSE,
sizeof(Vertex), (void *)offsetof(Vertex, pos));
log_success("Program %d initialized", i + 1);
}
ShaderProgram shaders_init(File *fragment_shaders, Context context) {
unsigned int i;
ShaderProgram program;
program.error = false;
program.last_width = context.width;
program.last_height = context.height;
init_textures(&program, context);
init_framebuffers(&program);
init_shaders(&program, fragment_shaders);
if (program.error) {
return program;
}
init_vertices(&program);
// create and link full shader programs
for (i = 0; i < FRAG_COUNT + 1; i++) {
init_single_program(&program, i, i == FRAG_COUNT);
}
// TODO functions
for (i = 0; i < TEX_COUNT; i++) {
program.draw_buffers[i] = GL_COLOR_ATTACHMENT0 + i;
}
return program;
}
void shaders_update(ShaderProgram program, File *fragment_shaders,
unsigned int i) {
bool result;
result = compile_shader(program.fragment_shaders[i], fragment_shaders[i].path,
fragment_shaders[i].content);
if (result) {
glLinkProgram(program.programs[i]);
log_success("Program %d updated", i + 1);
}
}
void shaders_apply(ShaderProgram program, Context context) {
unsigned int i, j;
GLuint subroutines[3];
vec2 resolution;
// viewport changed
if (context.width != program.last_width ||
context.height != program.last_height) {
// update viewport
glViewport(0, 0, context.width, context.height);
// clean and resize all textures
for (i = 0; i < TEX_COUNT; i++) {
glActiveTexture(GL_TEXTURE0 + i);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, context.width, context.height, 0,
GL_RGB, GL_UNSIGNED_BYTE, 0);
}
}
resolution[0] = (float)context.width;
resolution[1] = (float)context.height;
for (i = 0; i < FRAG_COUNT + 1; i++) {
// use specific shader program
glUseProgram(program.programs[i]);
if (i == FRAG_COUNT) {
// use default framebuffer (output)
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// clear buffer
glClear(GL_COLOR_BUFFER_BIT);
} else {
// use memory framebuffer
glBindFramebuffer(GL_FRAMEBUFFER, program.frame_buffers[0]);
// set fragment uniforms
glUniform1f(program.itime_locations[i], (const GLfloat)context.time);
glUniform1f(program.itempo_locations[i],
(const GLfloat)120.0f); // TODO TMP
glUniform1i(program.ifps_locations[i], (const GLint)context.fps);
glUniform2fv(program.ires_locations[i], 1, (const GLfloat *)&resolution);
// TODO tmp
subroutines[0] = program.sub_src_indexes[i][i == 0 ? 1 : 2];
subroutines[1] = program.sub_fx_indexes[i][i == 2 ? 1 : 0];
subroutines[2] = program.sub_mix_indexes[i][1];
glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 3, subroutines);
}
// set GL_TEXTURE(X) to uniform sampler2D frameX
for (j = 0; j < TEX_COUNT; j++) {
glUniform1i(program.frames_locations[i][j], j);
}
glDrawBuffers(TEX_COUNT, program.draw_buffers);
// draw output
glDrawArrays(GL_TRIANGLES, 0, 6);
}
}