Files
coffee_crisis_arcade_edition/source/jail_shader.cpp

288 lines
11 KiB
C++

#include "jail_shader.h"
#include <SDL2/SDL.h> // para SDL_Point
#include <stdlib.h> // para NULL, free, malloc, exit
#include <string.h> // para strncmp
#include <iostream> // para basic_ostream, char_traits, operator<<
#ifdef __APPLE__
#include "CoreFoundation/CoreFoundation.h"
#include <OpenGL/OpenGL.h>
#if ESSENTIAL_GL_PRACTICES_SUPPORT_GL3
#include <OpenGL/gl3.h>
#else // NOT ESSENTIAL_GL_PRACTICES_SUPPORT_GL3
#include <OpenGL/gl.h>
#endif // ESSENTIAL_GL_PRACTICES_SUPPORT_GL3
#else // NOT __APPLE__
#include <SDL2/SDL_opengl.h>
#endif // __APPLE__
namespace shader
{
SDL_Window *win = nullptr;
SDL_Renderer *renderer = nullptr;
GLuint programId = 0;
SDL_Texture *backBuffer = nullptr;
SDL_Point win_size = {320 * 4, 256 * 4};
SDL_Point tex_size = {320, 256};
bool usingOpenGL;
#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;
PFNGLLINKPROGRAMPROC glLinkProgram;
PFNGLVALIDATEPROGRAMPROC glValidateProgram;
PFNGLGETPROGRAMIVPROC glGetProgramiv;
PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog;
PFNGLUSEPROGRAMPROC glUseProgram;
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");
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");
return glCreateShader && glShaderSource && glCompileShader && glGetShaderiv &&
glGetShaderInfoLog && glDeleteShader && glAttachShader && glCreateProgram &&
glLinkProgram && glValidateProgram && glGetProgramiv && glGetProgramInfoLog &&
glUseProgram;
}
#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, nullptr);
// 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;
free(log);
}
glDeleteShader(result);
result = 0;
}
return result;
}
GLuint compileProgram(const char *vertexShaderSource, const char *fragmentShaderSource)
{
GLuint programId = 0;
GLuint vtxShaderId, fragShaderId;
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;
}
const bool init(SDL_Window *win, SDL_Texture *backBuffer, const char *vertexShader, const char *fragmentShader)
{
shader::win = win;
shader::renderer = SDL_GetRenderer(win);
shader::backBuffer = backBuffer;
SDL_GetWindowSize(win, &win_size.x, &win_size.y);
int access;
SDL_QueryTexture(backBuffer, nullptr, &access, &tex_size.x, &tex_size.y);
if (access != SDL_TEXTUREACCESS_TARGET)
{
throw std::runtime_error("ERROR FATAL: La textura debe tener SDL_TEXTUREACCESS_TARGET definido.");
}
SDL_RendererInfo rendererInfo;
SDL_GetRendererInfo(renderer, &rendererInfo);
if (!strncmp(rendererInfo.name, "opengl", 6))
{
#ifndef __APPLE__
if (!initGLExtensions())
{
std::cout << "WARNING: No s'han pogut inicialitzar les extensions d'OpenGL!" << std::endl;
usingOpenGL = false;
return false;
}
#endif
// Compilar el shader y dejarlo listo para usar.
programId = compileProgram(vertexShader, fragmentShader);
}
else
{
std::cout << "WARNING: El driver del renderer no es OpenGL." << std::endl;
usingOpenGL = false;
return false;
}
usingOpenGL = true;
return true;
}
void render()
{
GLint oldProgramId;
// Establece el color de fondo
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_SetRenderTarget(renderer, nullptr);
SDL_RenderClear(renderer);
if (usingOpenGL)
{
SDL_GL_BindTexture(backBuffer, nullptr, nullptr);
if (programId != 0)
{
glGetIntegerv(GL_CURRENT_PROGRAM, &oldProgramId);
glUseProgram(programId);
}
// Recupera el tamaño lógico configurado con SDL_RenderSetLogicalSize
int logicalW, logicalH;
SDL_RenderGetLogicalSize(renderer, &logicalW, &logicalH);
if (logicalW == 0 || logicalH == 0)
{
logicalW = win_size.x;
logicalH = win_size.y;
}
// Cálculo del viewport
int viewportX = 0, viewportY = 0, viewportW = win_size.x, viewportH = win_size.y;
SDL_bool useIntegerScale = SDL_RenderGetIntegerScale(renderer);
if (useIntegerScale)
{
// Calcula el factor de escalado entero máximo que se puede aplicar
int scaleX = win_size.x / logicalW;
int scaleY = win_size.y / logicalH;
int scale = (scaleX < scaleY ? scaleX : scaleY);
if (scale < 1)
scale = 1;
viewportW = logicalW * scale;
viewportH = logicalH * scale;
viewportX = (win_size.x - viewportW) / 2;
viewportY = (win_size.y - viewportH) / 2;
}
else
{
// Letterboxing: preserva la relación de aspecto usando una escala flotante
float windowAspect = static_cast<float>(win_size.x) / win_size.y;
float logicalAspect = static_cast<float>(logicalW) / logicalH;
if (windowAspect > logicalAspect)
{
viewportW = static_cast<int>(logicalAspect * win_size.y);
viewportX = (win_size.x - viewportW) / 2;
}
else
{
viewportH = static_cast<int>(win_size.x / logicalAspect);
viewportY = (win_size.y - viewportH) / 2;
}
}
glViewport(viewportX, viewportY, viewportW, viewportH);
// Configurar la proyección ortográfica usando el espacio lógico
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Queremos que el origen esté en la esquina superior izquierda del espacio lógico.
glOrtho(0, static_cast<GLdouble>(logicalW), static_cast<GLdouble>(logicalH), 0, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// Dibuja el quad con las coordenadas ajustadas.
// Se asignan las coordenadas de textura "normales" para que no quede espejado horizontalmente,
// y se mantiene el flip vertical para que la imagen no aparezca volteada.
glBegin(GL_TRIANGLE_STRIP);
// Vértice superior izquierdo
glTexCoord2f(0.0f, 1.0f);
glVertex2f(0.0f, 0.0f);
// Vértice superior derecho
glTexCoord2f(1.0f, 1.0f);
glVertex2f(static_cast<GLfloat>(logicalW), 0.0f);
// Vértice inferior izquierdo
glTexCoord2f(0.0f, 0.0f);
glVertex2f(0.0f, static_cast<GLfloat>(logicalH));
// Vértice inferior derecho
glTexCoord2f(1.0f, 0.0f);
glVertex2f(static_cast<GLfloat>(logicalW), static_cast<GLfloat>(logicalH));
glEnd();
SDL_GL_SwapWindow(win);
if (programId != 0)
{
glUseProgram(oldProgramId);
}
}
else
{
SDL_RenderCopy(renderer, backBuffer, nullptr, nullptr);
SDL_RenderPresent(renderer);
}
}
}