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Diffstat (limited to 'tests/OffscreenContext.cc')
| -rw-r--r-- | tests/OffscreenContext.cc | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/tests/OffscreenContext.cc b/tests/OffscreenContext.cc new file mode 100644 index 0000000..66b4ab3 --- /dev/null +++ b/tests/OffscreenContext.cc @@ -0,0 +1,196 @@ +#include "OffscreenContext.h" +#include "printutils.h" +#include "lodepng.h" + +// see http://www.gamedev.net/topic/552607-conflict-between-glew-and-sdl/ +#define NO_SDL_GLEXT +#include <GL/glew.h> + +#define GL_GLEXT_PROTOTYPES +#include <GL/gl.h> +#include <GL/glext.h> + +//#include <GL/gl.h> +//#include <GL/glu.h> // for gluCheckExtension +#include <SDL.h> + +// Simple error reporting macros to help keep the sample code clean +#define REPORT_ERROR_AND_EXIT(desc) { std::cout << desc << "\n"; return false; } +#define NULL_ERROR_EXIT(test, desc) { if (!test) REPORT_ERROR_AND_EXIT(desc); } + +struct OffscreenContext +{ + int width; + int height; + GLuint fbo; + GLuint colorbo; + GLuint depthbo; +}; + +void write_targa(const char *filename, GLubyte *pixels, int width, int height) +{ + FILE *f = fopen( filename, "w" ); + int y; + if (f) { + GLubyte header[] = { + 00,00,02, 00,00,00, 00,00,00, 00,00,00, + 0xff & width, 0xff & width >> 8, + 0xff & height, 0xff & height >> 8, + 32, 0x20 }; // next-to-last = bit depth + fwrite( header, sizeof(header), 1, f); + for (y=height-1; y>=0; y--) + fwrite( pixels + y*width*4, 4, width, f); + fclose(f); + } +} + +void write_png(const char *filename, GLubyte *pixels, int width, int height) +{ + size_t pixel_size = 4; + size_t dataout_size = -1; + GLubyte *dataout = (GLubyte*)malloc(width*height*pixel_size); // freed below + GLubyte *pixels_flipped = (GLubyte*)malloc(width*height*pixel_size); // freed below + for (int y=0;y<height;y++) { + for (int x=0;x<width;x++) { + int offs1 = y*width*pixel_size + x*pixel_size; + int offs2 = (height-1-y)*width*pixel_size + x*pixel_size; + pixels_flipped[offs1 ] = pixels[offs2 ]; + pixels_flipped[offs1+1] = pixels[offs2+1]; + pixels_flipped[offs1+2] = pixels[offs2+2]; + pixels_flipped[offs1+3] = pixels[offs2+3]; + } + } + //encoder.settings.zlibsettings.windowSize = 2048; + //LodePNG_Text_add(&encoder.infoPng.text, "Comment", "Created with LodePNG"); + + LodePNG_encode(&dataout, &dataout_size, pixels_flipped, width, height, LCT_RGBA, 8); + //LodePNG_saveFile(dataout, dataout_size, "blah2.png"); + FILE *f = fopen( filename, "w" ); + if (f) { + fwrite( dataout, 1, dataout_size, f); + fclose(f); + } + free(pixels_flipped); + free(dataout); +} + +OffscreenContext *create_offscreen_context(int w, int h) +{ + OffscreenContext *ctx = new OffscreenContext; + ctx->width = w; + ctx->height = h; + + // dummy window + SDL_Init(SDL_INIT_VIDEO); + SDL_SetVideoMode(ctx->width,ctx->height,32,SDL_OPENGL); + + // must come after openGL context init (done by dummy window) + // but must also come before various EXT calls + //glewInit(); + +/* + // Test if framebuffer objects are supported + const GLubyte* strExt = glGetString(GL_EXTENSIONS); + GLboolean fboSupported = gluCheckExtension((const GLubyte*)"GL_EXT_framebuffer_object", strExt); + if (!fboSupported) + REPORT_ERROR_AND_EXIT("Your system does not support framebuffer extension - unable to render scene"); + + printf("%i\n", (int)glGenFramebuffersEXT); + GLuint fbo; + //ctx->fbo = 0; + glGenFramebuffersEXT(1, &fbo); + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); + REPORTGLERROR("binding framebuffer"); + + + GLuint renderBuffer = 0; + GLuint depthBuffer = 0; + // Depth buffer to use for depth testing - optional if you're not using depth testing + glGenRenderbuffersEXT(1, &depthBuffer); + glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, depthBuffer); + glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, w, h); + REPORTGLERROR("creating depth render buffer"); + + // Render buffer to use for imaging + glGenRenderbuffersEXT(1, &renderBuffer); + glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, renderBuffer); + glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA8, w, h); + REPORTGLERROR("creating color render buffer"); + + glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, + GL_RENDERBUFFER_EXT, renderBuffer); + REPORTGLERROR("specifying color render buffer"); + + if (glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) != + GL_FRAMEBUFFER_COMPLETE_EXT) + REPORT_ERROR_AND_EXIT("Problem with OpenGL framebuffer after specifying color render buffer."); + + glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, + GL_RENDERBUFFER_EXT, depthBuffer); + REPORTGLERROR("specifying depth render buffer"); + + if (glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) != + GL_FRAMEBUFFER_COMPLETE_EXT) + REPORT_ERROR_AND_EXIT("Problem with OpenGL framebuffer after specifying depth render buffer."); +*/ +/* + glClearColor(1, 1, 1, 1); + glClear(GL_COLOR_BUFFER_BIT); + glBegin(GL_TRIANGLES); + glColor3f( 1, 0, 0); + glVertex3f( 0, 0, 0); + glVertex3f( 1, 0, 0); + glVertex3f( 0, 1, 0); + glEnd(); + SDL_GL_SwapBuffers(); +// sleep(2); +*/ + + int samplesPerPixel = 4; // R, G, B and A + +/* char * filename = "blah.tga"; + GLubyte pixels[ ctx->width * ctx->height * samplesPerPixel ]; + glReadPixels(0, 0, ctx->width, ctx->height, GL_BGRA, GL_UNSIGNED_BYTE, pixels); + printf("writing %s\n",filename); + write_targa(filename,pixels,ctx->width, ctx->height);*/ + return ctx; +} + +bool teardown_offscreen_context(OffscreenContext *ctx) +{ + // "un"bind my FBO +// glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); + + /* + * Cleanup + */ + return true; +} + +bool save_framebuffer(OffscreenContext *ctx, const char *filename) +{ + /* + * Extract the resulting rendering as an image + */ + + SDL_GL_SwapBuffers(); // show image + int samplesPerPixel = 4; // R, G, B and A + + GLubyte pixels[ ctx->width * ctx->height * samplesPerPixel ]; + glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, pixels); + //char * filename2="blah2.tga"; + //PRINTF("writing %s\n",filename2); + //write_targa(filename2,pixels,ctx->width, ctx->height); + //char * filename2="blah2.png"; + PRINTF("writing %s . . .",filename); + //write_targa(filename2,pixels,ctx->width, ctx->height); + write_png(filename,pixels,ctx->width, ctx->height); + PRINTF("written\n"); + + return true; +} + +void bind_offscreen_context(OffscreenContext *ctx) +{ +// glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, ctx->fbo); +} |