Graphics Reference
In-Depth Information
Example 6-1
Array of Structures
#define VERTEX_POS_SIZE 3 // x, y, and z
#define VERTEX_NORMAL_SIZE 3 // x, y, and z
#define VERTEX_TEXCOORD0_SIZE 2 // s and t
#define VERTEX_TEXCOORDl_SIZE 2 // s and t
#define VERTEX_POS_INDX 0
#define VERTEX_NORMAL_INDX 1
#define VERTEX_TEXCOORD0_INDX 2
#define VERTEX_TEXCOORDl_INDX 3
// the following 4 defines are used to determine the locations
// of various attributes if vertex data are stored as an array
// of structures
#define VERTEX_POS_OFFSET 0
#define VERTEX_NORMAL_OFFSET 3
#define VERTEX_TEXCOORD0_OFFSET 6
#define VERTEX_TEXC00RD1_0FFSET 8
#define VERTEX_ATTRIB_SIZE (VERTEX_POS_SIZE + \
VERTEX_NORMAL_SIZE + \
VERTEX_TEXCOORD0_SIZE + \
VERTEX_TEXC00RD1_SIZE)
float *p = (float*) malloc(numVertices * VERTEX_ATTRIB_SIZE
* sizeof(float));
// position is vertex attribute 0
glVertexAttribPointer(VERTEX_POS_INDX, VERTEX_POS_SIZE,
GL_FLOAT, GL_FALSE,
VERTEX_ATTRIB_SIZE * sizeof(float),
p);
// normal is vertex attribute 1
glVertexAttribPointer(VERTEX_NORMAL_INDX, VERTEX_NORMAL_SIZE,
GL_FLOAT, GL_FALSE,
VERTEX_ATTRIB_SIZE * sizeof(float),
(p + VERTEX_NORMAL_OFFSET));
// texture coordinate 0 is vertex attribute 2
glVertexAttribPointer(VERTEX_TEXCOORDO_INDX,
VERTEX_TEXCOORD0_SIZE,
GL_FLOAT, GL_FALSE,
VERTEX_ATTRIB_SIZE * sizeof(float),
(p + VERTEX_TEXCOORD0_OFFSET));
// texture coordinate 1 is vertex attribute 3
glVertexAttribPointer(VERTEX_TEXCOORDl_INDX,
(continues)
