texture.cpp

OPENGL2.0用于ARM11 3D处理

#include "stdafx.h"
#include <stdlib.h>
#include <stdio.h>

#include <gles/gles.h>
#include <math.h>


#define PI 3.141592f

extern int ReadBmp (const char *filename, unsigned char  *buffer, int *width, int *height);
extern void WriteBmp(const char *pFilename, const unsigned int *pBuffer, int nWidth, int nHeight);

static GLint TexWidth, TexHeight;
GLubyte CheckerData[64][64][4];
GLint *ImageData1;
GLint *SubImageData1;
GLfloat texangx, texangy, texangz;

GLvoid MakeCheckerImage (GLvoid)
{
	GLint i, j, c;

	for (i = 0; i < TexHeight; i ++)
	{
		for (j = 0; j < TexWidth; j++)
		{
			c = ((((i & 0x8) == 0) ^ ((j & 0x8)) == 0)) * 255;
			CheckerData[i][j][0] = (GLubyte) c;
			CheckerData[i][j][1] = (GLubyte) c;
			CheckerData[i][j][2] = (GLubyte) c;
			CheckerData[i][j][3] = (GLubyte) 255;
		}
	}
}

GLvoid CreateImage (GLint ImageId)
{
	GLint width, height;

	switch (ImageId)
	{
	case 1:
		width = 128;
		height = 128;
		ImageData1 = (GLint*) malloc (width * height * (sizeof (GLint)));
		ReadBmp ("kat_128_128.bmp",(unsigned char*) ImageData1, &TexWidth, &TexHeight);
		break;
	case 2:
		width = 74;
		height = 94;
		SubImageData1 = (GLint*) malloc (width * height * (sizeof (GLint)));
		ReadBmp ("Amoeba_74_94.bmp",(unsigned char*) SubImageData1, &TexWidth, &TexHeight);
	}
}

GLvoid FreeImage (GLint ImageId)
{
	switch (ImageId)
	{
	case 1:
		free (ImageData1);
		break;
	case 2:
		free (SubImageData1);
		break;
	}
}


void ReSizeGLScene_Texture (int w, int h)
{
	glMatrixMode (GL_PROJECTION);
	glLoadIdentity ();
	//glFrustumf (-15.0f, 15.0f, -20.0f, 20.0f, 0.30f, 200.0f);
	glOrthof(-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,
         		1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
	glMatrixMode (GL_MODELVIEW);
	//glTranslatef (10.0, 10.0, -10.0f);

	glLoadIdentity ();

	glViewport (0, 0, w, h);
}

int InitGL_Texture (void)
{
	GLuint texName;
	GLint CurrentTexWidth, CurrentTexHeight;

	glClearColor (0.0, 0.0, 0.0, 0.0);
	glEnable (GL_DEPTH_TEST);

	glGenTextures (1, &texName);
	glBindTexture (GL_TEXTURE_2D, texName);

	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

	CreateImage ( 1);
	CurrentTexWidth = TexWidth;
	CurrentTexHeight = TexHeight;

	glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, CurrentTexWidth, CurrentTexHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, ImageData1);
	FreeImage (1);

	return GL_TRUE;
}

#define LEVELS 20
#define ARCS 30 



static void DrawSphere () 
{
	GLfloat vertex[(ARCS + 1) * LEVELS * 3 * 2] = {0};
	GLfloat texture[(ARCS + 1) * LEVELS * 2 * 2] = {0};
	GLfloat x1, y1, z1, x2, y2, z2;
	GLfloat r;
	GLfloat levelstep, arcsstep;
	GLfloat cphi1, sphi1, cphi2, sphi2, ctheta, stheta;
	int index = 0; 
	int nindex = 0; 
	int tindex = 0;
	int i = 0, j = 0;
	
	glEnable (GL_TEXTURE_2D);
	glVertexPointer (3, GL_FLOAT, 0, vertex); 
//	glNormalPointer (GL_FLOAT, 0, normal);
	glTexCoordPointer (2, GL_FLOAT, 0, texture);

	r = 1;
	
	levelstep = PI / LEVELS ;
	arcsstep = (2.0f * PI) / ARCS;
	
	for (i = 0; i < LEVELS; i++) 
	{
		cphi1 = cos (i*levelstep);
		sphi1 = sin (i*levelstep);

		cphi2 = cos ((i + 1) * levelstep);
		sphi2 = sin ((i + 1) * levelstep);

		for (j = 0; j <= ARCS; j++) 
		{
			ctheta = cos (j * arcsstep);
			stheta = sin (j * arcsstep);
			x1 = r * ctheta * sphi1;
			y1 = r * stheta * sphi1; 
			z1 = r * cphi1;

			x2 = r * ctheta * sphi2;
			y2 = r * stheta * sphi2; 
			z2 = r * cphi2;


			vertex[index++] = x1;
			vertex[index++] = y1;
			vertex[index++] = z1;

			vertex[index++] = x2;
			vertex[index++] = y2;
			vertex[index++] = z2;

		/*	normal[nindex++] = ctheta * sphi1;
			normal[nindex++] = stheta * sphi1;
			normal[nindex++] = cphi1;

			normal[nindex++] = ctheta * sphi2;
			normal[nindex++] = stheta * sphi2;
			normal[nindex++] = cphi2;*/

			texture [tindex++] = j * (1.0f / ARCS);
			texture [tindex++] = i * (1.0f / LEVELS);
			
			texture [tindex++] = j * (1.0f / ARCS);
			texture [tindex++] = (i + 1) *(1.0f / LEVELS);

		}
	}
	
	glEnableClientState (GL_VERTEX_ARRAY);
	glEnableClientState (GL_TEXTURE_COORD_ARRAY);
	//glEnableClientState (GL_NORMAL_ARRAY);
	

//	glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

//	glColor4f (1.0f, 0.0f, 0.0f, 1.0f);
	
	for (i = 0; i < LEVELS; i++ ) 
	{
		glDrawArrays (GL_TRIANGLE_STRIP, i * 2.0f * (ARCS + 1) , (2.0f *(ARCS + 1)));
	}

	glDisableClientState (GL_VERTEX_ARRAY);
	//glDisableClientState (GL_NORMAL_ARRAY);
	glDisableClientState (GL_TEXTURE_COORD_ARRAY);
	glDisable (GL_TEXTURE_2D);
}



static void DrawAxis ()
{
	GLfloat axis[]  = {0.0, 0.0, 0.0, 
					   10.0 ,0.0, 0.0, 
					   0.0, 10.0, 0.0, 
					   0.0, 0.0, 10.0};
	GLubyte index[] = {0,1, 0, 2, 0,3};
	glVertexPointer (3, GL_FLOAT, 0, axis);

	glEnableClientState (GL_VERTEX_ARRAY);

	glColor4f (1.0, 1.0, 1.0, 1.0);
	glDrawElements (GL_LINES, 6, GL_UNSIGNED_BYTE, index);

	glDisableClientState (GL_VERTEX_ARRAY);
}

void TextureRender()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glMatrixMode(GL_MODELVIEW);	
	glLoadIdentity();
	glRotatef (30, 1.0f, 0.0f, 0.0f);
	glRotatef (-45, 0.0f, 1.0f, 0.0f);

	DrawAxis ();
	//DrawTexRect ();
	glRotatef (texangx, 1.0f, 0.0f, 0.0f);
	glRotatef (texangy, 0.0f, 1.0f, 0.0f);
	glRotatef (texangz, 0.0f, 0.0f, 1.0f);
	DrawSphere ();

	if (texangx >= 360.0f)
	{
		texangx = 1.0f;
	}
	else
	{
		texangx += 1.0f;
	}

	if (texangy >= 360.0f)
	{
		texangy = 2.0f;
	}
	else
	{
		texangy += 2.0f;
	}

	if (texangz >= 360.0f)
	{
		texangz = 3.0f;
	}
	else
	{
		texangz += 3.0f;
	}
}


int TextureDemo()
{	
	InitGL_Texture ();
    ReSizeGLScene_Texture(WINDOW_WIDTH, WINDOW_HEIGHT);

	texangx = 0;
	texangy = 0;
	texangz = 0;

	return 1;
}

int TextureDeinit()
{
	return 1;
}