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mini/source/backends/SDL3/shader.cpp
T

246 lines
10 KiB
C++

#if BACKEND == SDL3
#include "backends/backend.h"
#include "state.h"
#include "mini/file/file.h"
#include "mini/win/win.h"
#include <iostream>
#ifdef __APPLE__
#include <CoreFoundation/CoreFoundation.h>
#include <OpenGL/OpenGL.h>
#if ESSENTIAL_GL_PRACTICES_SUPPORT_GL3
#include <OpenGL/gl3.h>
#else
#include <OpenGL/gl.h>
#endif //!ESSENTIAL_GL_PRACTICES_SUPPORT_GL3
#else
#include <SDL3/SDL_opengl.h>
#include <SDL3/SDL_opengl_glext.h>
#endif
namespace backend
{
namespace shader
{
GLuint programId = 0;
SDL_Point win_size = {640, 480};
SDL_FPoint tex_size = {320, 240};
bool can_use_opengl = false;
bool using_opengl = false;
#ifndef __APPLE__
// I'm avoiding the use of GLEW or some extensions handler, but that
// doesn't mean you should...
PFNGLCREATESHADERPROC glCreateShader;
PFNGLSHADERSOURCEPROC glShaderSource;
PFNGLCOMPILESHADERPROC glCompileShader;
PFNGLGETSHADERIVPROC glGetShaderiv;
PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog;
PFNGLDELETESHADERPROC glDeleteShader;
PFNGLATTACHSHADERPROC glAttachShader;
PFNGLCREATEPROGRAMPROC glCreateProgram;
PFNGLDELETEPROGRAMPROC glDeleteProgram;
PFNGLLINKPROGRAMPROC glLinkProgram;
PFNGLVALIDATEPROGRAMPROC glValidateProgram;
PFNGLGETPROGRAMIVPROC glGetProgramiv;
PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog;
PFNGLUSEPROGRAMPROC glUseProgram;
PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation;
PFNGLACTIVETEXTUREPROC glActiveTexture;
bool initGLExtensions() {
glCreateShader = (PFNGLCREATESHADERPROC)SDL_GL_GetProcAddress("glCreateShader");
glShaderSource = (PFNGLSHADERSOURCEPROC)SDL_GL_GetProcAddress("glShaderSource");
glCompileShader = (PFNGLCOMPILESHADERPROC)SDL_GL_GetProcAddress("glCompileShader");
glGetShaderiv = (PFNGLGETSHADERIVPROC)SDL_GL_GetProcAddress("glGetShaderiv");
glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)SDL_GL_GetProcAddress("glGetShaderInfoLog");
glDeleteShader = (PFNGLDELETESHADERPROC)SDL_GL_GetProcAddress("glDeleteShader");
glAttachShader = (PFNGLATTACHSHADERPROC)SDL_GL_GetProcAddress("glAttachShader");
glCreateProgram = (PFNGLCREATEPROGRAMPROC)SDL_GL_GetProcAddress("glCreateProgram");
glDeleteProgram = (PFNGLDELETEPROGRAMPROC)SDL_GL_GetProcAddress("glDeleteProgram");
glLinkProgram = (PFNGLLINKPROGRAMPROC)SDL_GL_GetProcAddress("glLinkProgram");
glValidateProgram = (PFNGLVALIDATEPROGRAMPROC)SDL_GL_GetProcAddress("glValidateProgram");
glGetProgramiv = (PFNGLGETPROGRAMIVPROC)SDL_GL_GetProcAddress("glGetProgramiv");
glGetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC)SDL_GL_GetProcAddress("glGetProgramInfoLog");
glUseProgram = (PFNGLUSEPROGRAMPROC)SDL_GL_GetProcAddress("glUseProgram");
glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)SDL_GL_GetProcAddress("glGetUniformLocation");
glActiveTexture = (PFNGLACTIVETEXTUREPROC)SDL_GL_GetProcAddress("glActiveTexture");
return glCreateShader && glShaderSource && glCompileShader && glGetShaderiv &&
glGetShaderInfoLog && glDeleteShader && glAttachShader && glCreateProgram &&
glDeleteProgram && glLinkProgram && glValidateProgram && glGetProgramiv &&
glGetProgramInfoLog && glUseProgram && glGetUniformLocation;
}
#endif
GLuint compileShader(const char* source, GLuint shaderType) {
// Create ID for shader
GLuint result = glCreateShader(shaderType);
// Add define depending on shader type
const char *sources[2] = { shaderType==GL_VERTEX_SHADER?"#define VERTEX\n":"#define FRAGMENT\n", source };
// Define shader text
glShaderSource(result, 2, sources, NULL);
// Compile shader
glCompileShader(result);
//Check vertex shader for errors
GLint shaderCompiled = GL_FALSE;
glGetShaderiv( result, GL_COMPILE_STATUS, &shaderCompiled );
if (shaderCompiled != GL_TRUE)
{
std::cout << "Error en la compilación: " << result << "!" << std::endl;
GLint logLength;
glGetShaderiv(result, GL_INFO_LOG_LENGTH, &logLength);
if (logLength > 0)
{
GLchar *log = (GLchar*)malloc(logLength);
glGetShaderInfoLog(result, logLength, &logLength, log);
std::cout << "Shader compile log:" << log << std::endl;
//std::cout << source << std::endl;
free(log);
}
glDeleteShader(result);
result = 0;
}
return result;
}
GLuint compileProgram(const char* vertexShaderSource, const char* fragmentShaderSource)
{
GLuint programId = 0;
GLuint vtxShaderId, fragShaderId;
if (programId != 0) glDeleteProgram(programId);
programId = glCreateProgram();
vtxShaderId = compileShader(vertexShaderSource, GL_VERTEX_SHADER);
fragShaderId = compileShader(fragmentShaderSource?fragmentShaderSource:vertexShaderSource, GL_FRAGMENT_SHADER);
if(vtxShaderId && fragShaderId)
{
// Associate shader with program
glAttachShader(programId, vtxShaderId);
glAttachShader(programId, fragShaderId);
glLinkProgram(programId);
glValidateProgram(programId);
// Check the status of the compile/link
GLint logLen;
glGetProgramiv(programId, GL_INFO_LOG_LENGTH, &logLen);
if (logLen > 0)
{
char* log = (char*) malloc(logLen * sizeof(char));
// Show any errors as appropriate
glGetProgramInfoLog(programId, logLen, &logLen, log);
std::cout << "Prog Info Log: " << std::endl << log << std::endl;
free(log);
}
}
if (vtxShaderId) glDeleteShader(vtxShaderId);
if (fragShaderId) glDeleteShader(fragShaderId);
return programId;
}
void init(const char* vshader, const char* fshader)
{
int filesize;
char *vshaderfile = mini::file::getfilebuffer(vshader, filesize, true);
char *fshaderfile = nullptr;
if (fshader) { fshaderfile = mini::file::getfilebuffer(fshader, filesize, true); }
SDL_GetWindowSize(video::window, &win_size.x, &win_size.y);
SDL_GetTextureSize(video::tex_shader, &tex_size.x, &tex_size.y);
SDL_PropertiesID props = SDL_GetTextureProperties(video::tex_shader);
int access = SDL_GetNumberProperty(props, SDL_PROP_TEXTURE_ACCESS_NUMBER, -1);
if (access != SDL_TEXTUREACCESS_TARGET) {
std::cout << "ERROR FATAL: La textura per al render ha de tindre SDL_TEXTUREACCESS_TARGET definit." << std::endl;
::exit(1);
}
const char * renderer_name = SDL_GetRendererName(backend::video::renderer);
if(!strncmp(renderer_name, "opengl", 6)) {
#ifndef __APPLE__
static bool gl_extensions_initialized = false;
if (!gl_extensions_initialized) {
if (!initGLExtensions()) {
std::cout << "WARNING: No s'han pogut inicialitzar les extensions d'OpenGL!" << std::endl;
can_use_opengl = false;
return;
}
gl_extensions_initialized = true;
}
#endif
// Compilar el shader y dejarlo listo para usar.
if (!vshaderfile) {
can_use_opengl = false;
return;
}
programId = compileProgram(vshaderfile, fshaderfile);
} else {
std::cout << "WARNING: El driver del renderer no es OpenGL." << std::endl;
can_use_opengl = false;
return;
}
can_use_opengl = true;
return;
}
void enable() { if (can_use_opengl) using_opengl = true; }
void disable() { using_opengl = false; }
void render()
{
SDL_FlushRenderer(backend::video::renderer);
SDL_SetRenderTarget(backend::video::renderer, NULL);
SDL_SetRenderDrawColor(backend::video::renderer, 0, 0, 0, 255);
SDL_RenderClear(backend::video::renderer);
SDL_FlushRenderer(backend::video::renderer);
if (using_opengl)
{
GLint oldProgramId;
if (programId != 0)
{
glGetIntegerv(GL_CURRENT_PROGRAM, &oldProgramId);
glUseProgram(programId);
}
glEnable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, 1);
glViewport(0, 0, win_size.x, win_size.y);
glBegin(GL_TRIANGLE_STRIP);
glTexCoord2f(0.0f, 0.0f);
glVertex2f(-1.0f, -1.0f);
glTexCoord2f(tex_size.x, 0.0f);
glVertex2f(1.0f, -1.0f);
glTexCoord2f(0.0f, tex_size.y);
glVertex2f(-1.0f, 1.0f);
glTexCoord2f(tex_size.x, tex_size.y);
glVertex2f(1.0f, 1.0f);
glEnd();
SDL_GL_SwapWindow(backend::video::window);
if (programId != 0) glUseProgram(oldProgramId);
} else {
SDL_RenderTexture(backend::video::renderer, backend::video::tex_shader, NULL, NULL);
SDL_RenderPresent(backend::video::renderer);
}
if (glGetError()) { printf("GLERROR!\n"); ::exit(1); }
}
}
}
#endif