我正在尝试将sdl2纹理绑定到 glsl 着色器，尽管我不完全确定如何？我正在使用一个名为glfx的库来处理 glsl 着色器，并且我也一直在帮助开发这个库。我很确定我做的一切都是正确的，但是当我调用 SDL_GL_BindTexture 时它崩溃了。谁能看到我做错了什么？
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <string>
#include <GL/glew.h>
#include <GL/glfx.h>
#include <SDL2/SDL.h>
#include <FreeImage.h>
int main()
{
SDL_Window *mainwindow;
SDL_Renderer *renderer;
SDL_GLContext maincontext;
SDL_Init( SDL_INIT_VIDEO );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 3 );
SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 2 );
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 24 );
SDL_CreateWindowAndRenderer( 512, 512, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN, &mainwindow, &renderer );
maincontext = SDL_GL_CreateContext( mainwindow );
glewExperimental = GL_TRUE;
glewInit( );
fprintf( stdout, "%s\n", glGetString(GL_VERSION) );
fprintf( stdout, "%s\n", glGetString(GL_SHADING_LANGUAGE_VERSION) );
FIBITMAP* dib = FreeImage_Load( FIF_PNG, "test.png" );
uint32_t w = FreeImage_GetWidth( dib );
uint32_t h = FreeImage_GetHeight( dib );
dib = FreeImage_ConvertTo32Bits( dib );
BYTE* pixeles = FreeImage_GetBits( dib );
GLubyte* textura = new GLubyte[4*w*h];
SDL_Texture* texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STATIC, w, h );
const SDL_Rect rect = { 0, 0, w, h };
int pitch = 32;
SDL_LockTexture( texture, &rect, (void**)&textura, &pitch );
for( uint32_t j = 0; j < w * h; j++ )
{
textura[j*4+0] = pixeles[j*4+2];
textura[j*4+1] = pixeles[j*4+1];
textura[j*4+2] = pixeles[j*4+0];
textura[j*4+3] = pixeles[j*4+3];
}
SDL_UnlockTexture( texture );
FreeImage_Unload( dib );
delete [] textura;
int effect = glfxGenEffect( );
std::string shader;
shader ="struct VSinput\n"
"{\n"
" vec3 Position;\n"
"};\n"
"shader VSmain(in VSinput VSin, out vec2 TexCoord)\n"
"{\n"
" gl_Position = vec4(VSin.Position, 1.0);\n"
" TexCoord = vec2( 0.8, 0.8 );\n"
"};\n"
"uniform sampler2D gColorMap;\n"
"shader FSmain(in vec2 TexCoord, out vec4 FragColor)\n"
"{\n"
" FragColor = texture(gColorMap, TexCoord);\n"
"}\n"
"program SimpleTechnique\n"
"{\n"
" vs(150) = VSmain();\n"
" fs(150) = FSmain();\n"
"};\0";
glfxParseEffectFromMemory( effect, shader.c_str() );
int shaderProg = glfxCompileProgram( effect, "SimpleTechnique" );
if (shaderProg < 0)
{
std::string log = glfxGetEffectLog(effect);
fprintf( stderr, "%s\n", log.c_str() );
}
glClearColor ( 0.0, 0.0, 1.0, 1.0 );
glClear ( GL_COLOR_BUFFER_BIT );
float* vert = new float[9];
vert[0] = 0.0; vert[1] = 0.5; vert[2] =-1.0;
vert[3] =-1.0; vert[4] =-0.5; vert[5] =-1.0;
vert[6] = 1.0; vert[7] =-0.5; vert[8] =-1.0;
unsigned int m_vaoID;
unsigned int m_vboID;
glGenVertexArrays( 1, &m_vaoID );
glBindVertexArray( m_vaoID );
glGenBuffers( 1, &m_vboID );
glBindBuffer( GL_ARRAY_BUFFER, m_vboID );
glBufferData( GL_ARRAY_BUFFER, 9 * sizeof(GLfloat), vert, GL_STATIC_DRAW );
glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 0, 0 );
glEnableVertexAttribArray( 0 );
glEnable( GL_TEXTURE_2D );
int loc = glGetUniformLocation( shaderProg, "gColorMap" );
glActiveTexture( GL_TEXTURE0 );
SDL_GL_BindTexture(texture, NULL, NULL );
glUniform1i( loc, 0 );
glUseProgram( shaderProg );
glDrawArrays( GL_TRIANGLES, 0, 3 );
glDisableVertexAttribArray( 0 );
glBindVertexArray( 0 );
delete[] vert;
glBindBuffer( GL_ARRAY_BUFFER, 0 );
glDeleteBuffers( 1, &m_vboID );
glDeleteVertexArrays( 1, &m_vaoID );
SDL_GL_SwapWindow( mainwindow );
SDL_Delay( 2000 );
SDL_GL_DeleteContext( maincontext );
SDL_DestroyWindow( mainwindow );
SDL_Quit( );
return 0;
}