Attachment 45424 Details for Bug 36065 – sample app that reproduces the issue

sample app that reproduces the issue

vbo_stride_fail.cpp (text/plain), 3.99 KB, created by Pierre-Eric Pelloux-Prayer on 2011-04-08 08:44:47 UTC

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Creator: Pierre-Eric Pelloux-Prayer

Created: 2011-04-08 08:44:47 UTC

Size: 3.99 KB

patch

obsolete

>/*
>Compile with :
>g++ vbo_stride_fail.cpp -g -lglfw -lGL -lGLEW -lGLU -o vbo_fail
>
>*/
>
>
>#include <GL/glew.h>
>#include <GL/glfw.h>
>#include <GL/gl.h>
>#include <cassert>
>#include <iostream>
>
>struct Vector3 {
>    Vector3(float _x, float _y, float _z) : x(_x), y(_y), z(_z) {}
>	union {
>		struct { float x, y, z; };
>		struct { float xyz[3]; };
>	};
>};
>
>struct Color {
>    Color(unsigned char _r, unsigned char _g, unsigned char _b) : 
>        r(_r), g(_g), b(_b) {}
>
>    union {
>        struct { unsigned char r,g,b; };
>        struct { unsigned char rgb[3];};
>    };
>};
>
>
>#define VERTEX_COUNT 3
>struct Vector3 pos[VERTEX_COUNT] = {
>    Vector3(-1, -1, 0),
>    Vector3(-1, 1, 0),
>    Vector3(1, 1, 0)
>
>};
>
>struct Color col[VERTEX_COUNT] = {
>    Color(255, 0,0),
>    Color(0, 255, 0),
>    Color(0, 0, 255)
>};
>
>
>int copyVec3(const Vector3& data, unsigned char* out) {
>	float* fout = (float*) out;
>	*fout++ = data.x;
>	*fout++ = data.y;
>	*fout++ = data.z;
>	
>	return sizeof(data);
>}
>
>int copyColor(const Color& data, unsigned char* fout) {
>	*fout++ = data.r;
>	*fout++ = data.g;
>	*fout++ = data.b;
>	
>	return sizeof(data);
>}
>
>
>int fillVboBuffer(unsigned char** buffer, unsigned int** indices, int& outSizePerEntry) {
>    outSizePerEntry = 0;
>    outSizePerEntry += sizeof(Vector3); // position
>    outSizePerEntry += 3 * sizeof(char); // color
>
>    (*buffer) = new unsigned char[outSizePerEntry * VERTEX_COUNT];
>    (*indices) = new unsigned int[outSizePerEntry];
>
>    int index = 0;
>
>    for(int i=0; i<VERTEX_COUNT; ++i) {
>        index += copyVec3(pos[i], &(*buffer)[index]);
>        index += copyColor(col[i] , &(*buffer)[index]);
>
>        (*indices)[i] = i;
>    }
>
>    assert(index == VERTEX_COUNT * outSizePerEntry);
>
>    return VERTEX_COUNT;
>}
>
>#define BUFFER_OFFSET(_offset) ((char *)NULL + (_offset))
>#define CHECK_GL_ERROR {GLenum err = glGetError(); if (err != GL_NO_ERROR) { std::cout << "Error : " << gluErrorString(err) << std::endl; assert(false); }}
>
>int main() {
>    glfwInit();
>
>    glfwOpenWindow(320, 200, 8, 8, 8, 8, 8, 1, GLFW_WINDOW);
>
>    glewInit();
>
>    GLuint vbos[2];
>    unsigned char* tmp;
>    unsigned int* indices;
>
>    // create 2 VBOs
>    glGenBuffers(2, vbos);
>
>    glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
>    int sizePerEntry = 0;
>    int entryCount = fillVboBuffer(&tmp, &indices, sizePerEntry);
>    glBufferData(GL_ARRAY_BUFFER, entryCount * sizePerEntry, tmp, GL_STATIC_DRAW);
>	glBindBuffer(GL_ARRAY_BUFFER, 0);
>	
>	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbos[1]);
>	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned int) * entryCount, indices, GL_STATIC_DRAW);
>	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
>
>    // setup camera
>	glMatrixMode(GL_PROJECTION);
>	glLoadIdentity();
>	gluPerspective(70, 320.0/200.0, 0.1, 200);
>	glMatrixMode(GL_MODELVIEW);
>	glLoadIdentity();
>	gluLookAt(
>			0, 0, 3,
>			0, 0, 0,
>			0, 1, 0);
>    glClearColor(1,1,1,1);
>    
>    glDisable(GL_LIGHTING);
>	glDisable(GL_BLEND);
>	glDisable(GL_TEXTURE_2D);
>	glDisable(GL_DITHER);
>	glDisable(GL_CULL_FACE);
>    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);  
>
>    while(true) {
>        CHECK_GL_ERROR
>        glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT );
>
>#if 0
>        // render : immediate mode
>        glBegin(GL_TRIANGLES);
>        for(int i=0; i<entryCount; ++i) {
>            glColor3ubv(col[i].rgb);
>            glVertex3fv(pos[i].xyz);
>        }
>        glEnd();
>#else
>        // render : vbo mode
>        glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
>
>        glVertexPointer( 3, GL_FLOAT, sizePerEntry, BUFFER_OFFSET(0));
>        glColorPointer( 3, GL_UNSIGNED_BYTE, sizePerEntry, BUFFER_OFFSET(sizeof(Vector3)) );
>
>        glEnableClientState( GL_VERTEX_ARRAY );
>        glEnableClientState( GL_COLOR_ARRAY );
>
>        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbos[1]);
>
>        glDrawElements(GL_TRIANGLES, entryCount, GL_UNSIGNED_INT, 0);
>
>        glDisableClientState( GL_VERTEX_ARRAY );
>        glDisableClientState( GL_COLOR_ARRAY );
>#endif
>        glfwSwapBuffers();
>
>        if (glfwGetKey( GLFW_KEY_ESC ) || !glfwGetWindowParam( GLFW_OPENED )) break;
>    }
>
>    return 0;
>}

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Attachments on bug 36065: 45415 | 45424

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