Attachment 121440 Details for Bug 93955 – makecurrent.c

makecurrent.c

makecurrent.c (text/plain), 5.79 KB, created by almos on 2016-02-01 14:49:12 UTC

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Creator: almos

Created: 2016-02-01 14:49:12 UTC

Size: 5.79 KB

patch

obsolete

>// gcc -std=c99 makecurrent.c -o makecurrent -lGL -lGLU -lglut -lm -W -Wall -Wextra -ggdb
>
>#include <stdio.h>
>#include <stdlib.h>
>#include <string.h>
>#include <math.h>
>#include <assert.h>
>
>#define GL_GLEXT_PROTOTYPES
>#include <GL/gl.h>
>#include <GL/glext.h>
>#include <GL/glut.h>
>#include <GL/glx.h>
>
>static int width = 800;
>static int height = 400;
>
>GLuint tex0;
>GLuint tex1;
>
>GLboolean enableMakeCurrent = GL_TRUE;
>
>int pbuffer;
>
>static void initTextures(void)
>{
>    float scratch[32*32*3], *ptr;
>
>    // tex0: chessboard
>    ptr = scratch;
>    for (int i=0; i<32; ++i) {
>        for (int j=0; j<32; ++j) {
>            int ii = (i>>1)&1;
>            int jj = (j>>1)&1;
>            float val = ii==jj ? 1.0f : 0.0f;
>            ptr[0] = val;
>            ptr[1] = val;
>            ptr[2] = val;
>            ptr += 3;
>        }
>    }
>    glGenTextures(1, &tex0);
>    glBindTexture(GL_TEXTURE_2D, tex0);
>    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 32, 32, 0, GL_RGB, GL_FLOAT, (void*)scratch);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
>
>    // tex1: rainbow
>    ptr = scratch;
>    for (int i=0; i<32; ++i) {
>        for (int j=0; j<32; ++j) {
>            ptr[0] = 1.0f*i/32.0f;
>            ptr[1] = 1.0f*j/32.0f;
>            ptr[2] = (32-i-j)/32.0f;
>            ptr += 3;
>        }
>    }
>    glGenTextures(1, &tex1);
>    glBindTexture(GL_TEXTURE_2D, tex1);
>    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 32, 32, 0, GL_RGB, GL_FLOAT, (void*)scratch);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
>    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
>}
>
>static void display(void)
>{
>    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
>    glActiveTextureARB(GL_TEXTURE0);
>    glEnable(GL_TEXTURE_2D);
>    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
>
>    glBindTexture(GL_TEXTURE_2D, tex0);
>    glBegin(GL_QUADS);
>    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 0.0);
>    glVertex3f(0.0, 0.0, -0.0);
>    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 0.0);
>    glVertex3f(1.0, 0.0, -0.5);
>    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 1.0);
>    glVertex3f(1.0, 1.0, -1.0);
>    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 1.0);
>    glVertex3f(0.0, 1.0, -0.5);
>    glEnd();
>
>    if (enableMakeCurrent) {
>        Display *dpy = glXGetCurrentDisplay();
>        int current_drawable = glXGetCurrentDrawable();
>        GLXContext context = glXGetCurrentContext();
>        glXMakeCurrent(dpy, pbuffer, context); // Issue #1: Mesa warning: MakeCurrent: incompatible visuals for context and drawbuffer (pbuffer has no depth or stencil)
>        glColor3f(1.0f, 0.0f, 1.0f); // this is no-op because of the above
>        glXMakeCurrent(dpy, current_drawable, context);
>        // Issue #2: depth buffer is now lost (so is stencil), subsequent rendering fails depth test
>        //      because the newly allocated depth buffer is all zeros
>        //      (with DRI3 the already drawn image is partially overwritten with noise, DRI2 only looses the non-color buffers)
>    }
>
>    glBindTexture(GL_TEXTURE_2D, tex1);
>    glBegin(GL_QUADS);
>    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 0.0);
>    glVertex3f(0.0, 0.0, -1.0);
>    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 0.0);
>    glVertex3f(1.0, 0.0, -0.5);
>    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 1.0);
>    glVertex3f(1.0, 1.0, -0.0);
>    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 1.0);
>    glVertex3f(0.0, 1.0, -0.5);
>    glEnd();
>
>    glutSwapBuffers();
>}
>
>static void reshape(int w, int h)
>{
>    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
>    glMatrixMode(GL_PROJECTION);
>    glLoadIdentity();
>    glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
>    glMatrixMode(GL_MODELVIEW);
>    glLoadIdentity();
>}
>
>static void keyboard(unsigned char key, int x, int y)
>{
>    (void)x;
>    (void)y;
>    if (key == ' ') {
>        enableMakeCurrent = !enableMakeCurrent;
>        printf("MakeCurrent is now %sabled\n", enableMakeCurrent?"en":"dis");
>        glutPostRedisplay();
>    } else if (key == 'q' || key == 27 /* ESC */) {
>        exit(0);
>    }
>}
>
>static const int attrib_list[] = {
>    GLX_RED_SIZE, 8,
>    GLX_GREEN_SIZE, 8,
>    GLX_BLUE_SIZE, 8,
>    GLX_ALPHA_SIZE, 8,
>    /*GLX_DEPTH_SIZE, 24,
>    GLX_STENCIL_SIZE, 8,*/
>    GLX_DOUBLEBUFFER, GL_FALSE,
>    GLX_DRAWABLE_TYPE, GLX_PBUFFER_BIT,
>    GLX_RENDER_TYPE, GLX_RGBA_BIT,
>    0};
>
>static const int fb_size[] = {
>    GLX_PBUFFER_WIDTH, 512,
>    GLX_PBUFFER_HEIGHT, 512,
>    0};
>
>static void init(void)
>{
>    glColor3f(0.0f, 1.0f, 0.0f);
>    glEnable(GL_DEPTH_TEST);
>
>    initTextures();
>
>    Display *dpy = glXGetCurrentDisplay();
>
>    int nelements = 0;
>    GLXFBConfig *configs = glXChooseFBConfig(dpy, 0, attrib_list, &nelements);
>    printf("got %d configs\n", nelements);
>    for (int i=0; i<nelements; i++) {
>        int xid = 0;
>        int attr = 0;
>        if (glXGetFBConfigAttrib(dpy, configs[i], GLX_FBCONFIG_ID, &xid))
>            assert(!"Can't get fbconfig xid");
>        if (glXGetFBConfigAttrib(dpy, configs[i], GLX_DEPTH_SIZE, &attr))
>            assert(!"Can't get fbconfig attr");
>
>        printf("xid %#x attr %d\n", xid, attr);
>    }
>    pbuffer = glXCreatePbuffer(dpy, configs[0], fb_size);
>    assert(pbuffer);
>}
>
>
>static void fini(void)
>{
>}
>
>int main(int argc, char **argv)
>{
>    glutInit(&argc, argv);
>    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL);
>    glutInitWindowSize(width, height);
>    glutCreateWindow("Test program for glXMakeCurrent()");
>
>    glutDisplayFunc(display);
>    glutReshapeFunc(reshape);
>    glutKeyboardFunc(keyboard);
>    glutIdleFunc(glutPostRedisplay);
>
>    init();
>
>    glutMainLoop();
>
>    fini();
>}
>

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