diff options
Diffstat (limited to 'progs/trivial/tri-fbo-tex-mip.c')
-rw-r--r-- | progs/trivial/tri-fbo-tex-mip.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/progs/trivial/tri-fbo-tex-mip.c b/progs/trivial/tri-fbo-tex-mip.c new file mode 100644 index 00000000000..6a6254fa50f --- /dev/null +++ b/progs/trivial/tri-fbo-tex-mip.c @@ -0,0 +1,269 @@ +/* + * Test GL_EXT_framebuffer_object render-to-texture + * + * Draw a teapot into a texture image with stenciling. + * Then draw a textured quad using that texture. + * + * Brian Paul + * 18 Apr 2005 + */ + + +#include <GL/glew.h> +#include <GL/glut.h> +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <math.h> + +/* For debug */ + + +static int Win = 0; +static int Width = 512, Height = 512; + +static GLenum TexTarget = GL_TEXTURE_2D; +static int TexWidth = 512, TexHeight = 512; + +static GLuint MyFB; +static GLuint TexObj; +static GLboolean Anim = GL_FALSE; +static GLfloat Rot = 0.0; +static GLuint TextureLevel = 4; /* which texture level to render to */ +static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */ + + +static void +CheckError(int line) +{ + GLenum err = glGetError(); + if (err) { + printf("GL Error 0x%x at line %d\n", (int) err, line); + } +} + + +static void +Idle(void) +{ + Rot = glutGet(GLUT_ELAPSED_TIME) * 0.1; + glutPostRedisplay(); +} + + +static void +RenderTexture(void) +{ + GLenum status; + + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + glTranslatef(0.0, 0.0, -15.0); + + if (1) { + /* draw to texture image */ + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB); + + status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT); + if (status != GL_FRAMEBUFFER_COMPLETE_EXT) { + printf("Framebuffer incomplete!!!\n"); + } + + glViewport(0, 0, + TexWidth / (1 << TextureLevel), + TexHeight / (1 << TextureLevel)); + glClearColor(0.5, 0.5, 1.0, 0.0); + glClear(GL_COLOR_BUFFER_BIT); + + CheckError(__LINE__); + + glBegin(GL_POLYGON); + glColor3f(1, 0, 0); + glVertex2f(-1, -1); + glColor3f(0, 1, 0); + glVertex2f(1, -1); + glColor3f(0, 0, 1); + glVertex2f(0, 1); + glEnd(); + + /* Bind normal framebuffer */ + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); + } + else { + } + + CheckError(__LINE__); +} + + + +static void +Display(void) +{ + float ar = (float) Width / (float) Height; + + RenderTexture(); + + /* draw textured quad in the window */ + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + glTranslatef(0.0, 0.0, -7.0); + + glViewport(0, 0, Width, Height); + + glClearColor(0.25, 0.25, 0.25, 0); + glClear(GL_COLOR_BUFFER_BIT); + + glPushMatrix(); + glRotatef(Rot, 0, 1, 0); + glEnable(TexTarget); + glBindTexture(TexTarget, TexObj); + + { + glBegin(GL_POLYGON); + glColor3f(0.25, 0.25, 0.25); + glTexCoord2f(0, 0); + glVertex2f(-1, -1); + glTexCoord2f(1, 0); + glVertex2f(1, -1); + glColor3f(1.0, 1.0, 1.0); + glTexCoord2f(1, 1); + glVertex2f(1, 1); + glTexCoord2f(0, 1); + glVertex2f(-1, 1); + glEnd(); + } + + glPopMatrix(); + glDisable(TexTarget); + + glutSwapBuffers(); + CheckError(__LINE__); +} + + +static void +Reshape(int width, int height) +{ + glViewport(0, 0, width, height); + Width = width; + Height = height; +} + + +static void +CleanUp(void) +{ + glDeleteFramebuffersEXT(1, &MyFB); + + glDeleteTextures(1, &TexObj); + + glutDestroyWindow(Win); + + exit(0); +} + + +static void +Key(unsigned char key, int x, int y) +{ + (void) x; + (void) y; + switch (key) { + case 'a': + Anim = !Anim; + if (Anim) + glutIdleFunc(Idle); + else + glutIdleFunc(NULL); + break; + case 's': + Rot += 2.0; + break; + case 27: + CleanUp(); + break; + } + glutPostRedisplay(); +} + + +static void +Init(int argc, char *argv[]) +{ + if (!glutExtensionSupported("GL_EXT_framebuffer_object")) { + printf("GL_EXT_framebuffer_object not found!\n"); + exit(0); + } + + printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); + + + /* Make texture object/image */ + glGenTextures(1, &TexObj); + glBindTexture(TexTarget, TexObj); + glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST); + glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel); + glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel); + + glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0, + GL_RGBA, GL_UNSIGNED_BYTE, NULL); + glTexImage2D(TexTarget, TextureLevel, TexIntFormat, + TexWidth / (1 << TextureLevel), TexHeight / (1 << TextureLevel), 0, + GL_RGBA, GL_UNSIGNED_BYTE, NULL); + + + glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); + + + + + /* gen framebuffer id, delete it, do some assertions, just for testing */ + glGenFramebuffersEXT(1, &MyFB); + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB); + assert(glIsFramebufferEXT(MyFB)); + + + CheckError(__LINE__); + + /* Render color to texture */ + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, + TexTarget, TexObj, TextureLevel); + + + + CheckError(__LINE__); + + /* bind regular framebuffer */ + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); + + +} + + +int +main(int argc, char *argv[]) +{ + glutInit(&argc, argv); + glutInitWindowPosition(0, 0); + glutInitWindowSize(Width, Height); + glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE); + Win = glutCreateWindow(argv[0]); + glewInit(); + glutReshapeFunc(Reshape); + glutKeyboardFunc(Key); + glutDisplayFunc(Display); + if (Anim) + glutIdleFunc(Idle); + Init(argc, argv); + glutMainLoop(); + return 0; +} |