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/*
* Copyright (C) 2008 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* Draw a triangle with X/EGL and OpenGL ES 1.x
* Brian Paul
* 5 June 2008
*/
#define USE_FIXED_POINT 0
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <GLES/gl.h> /* use OpenGL ES 1.x */
#include <GLES/glext.h>
#include <EGL/egl.h>
#include "eglut.h"
#define FLOAT_TO_FIXED(X) ((X) * 65535.0)
static GLfloat view_rotx = 0.0, view_roty = 0.0, view_rotz = 0.0;
static void
draw(void)
{
#if USE_FIXED_POINT
static const GLfixed verts[3][2] = {
{ -65536, -65536 },
{ 65536, -65536 },
{ 0, 65536 }
};
static const GLfixed colors[3][4] = {
{ 65536, 0, 0, 65536 },
{ 0, 65536, 0 , 65536},
{ 0, 0, 65536 , 65536}
};
#else
static const GLfloat verts[3][2] = {
{ -1, -1 },
{ 1, -1 },
{ 0, 1 }
};
static const GLfloat colors[3][4] = {
{ 1, 0, 0, 1 },
{ 0, 1, 0, 1 },
{ 0, 0, 1, 1 }
};
#endif
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(view_rotx, 1, 0, 0);
glRotatef(view_roty, 0, 1, 0);
glRotatef(view_rotz, 0, 0, 1);
{
#if USE_FIXED_POINT
glVertexPointer(2, GL_FIXED, 0, verts);
glColorPointer(4, GL_FIXED, 0, colors);
#else
glVertexPointer(2, GL_FLOAT, 0, verts);
glColorPointer(4, GL_FLOAT, 0, colors);
#endif
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
/* draw triangle */
glDrawArrays(GL_TRIANGLES, 0, 3);
/* draw some points */
glPointSizex(FLOAT_TO_FIXED(15.5));
glDrawArrays(GL_POINTS, 0, 3);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
}
if (0) {
/* test code */
GLfixed size;
glGetFixedv(GL_POINT_SIZE, &size);
printf("GL_POINT_SIZE = 0x%x %f\n", size, size / 65536.0);
}
glPopMatrix();
}
/* new window size or exposure */
static void
reshape(int width, int height)
{
GLfloat ar = (GLfloat) width / (GLfloat) height;
glViewport(0, 0, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
#ifdef GL_VERSION_ES_CM_1_0
glFrustumf(-ar, ar, -1, 1, 5.0, 60.0);
#else
glFrustum(-ar, ar, -1, 1, 5.0, 60.0);
#endif
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -10.0);
}
static void
test_query_matrix(void)
{
PFNGLQUERYMATRIXXOESPROC procQueryMatrixx;
typedef void (*voidproc)();
GLfixed mantissa[16];
GLint exponent[16];
GLbitfield rv;
int i;
procQueryMatrixx = (PFNGLQUERYMATRIXXOESPROC) eglGetProcAddress("glQueryMatrixxOES");
assert(procQueryMatrixx);
/* Actually try out this one */
rv = (*procQueryMatrixx)(mantissa, exponent);
for (i = 0; i < 16; i++) {
if (rv & (1<<i)) {
printf("matrix[%d] invalid\n", i);
}
else {
printf("matrix[%d] = %f * 2^(%d)\n", i, mantissa[i]/65536.0, exponent[i]);
}
}
assert(!eglGetProcAddress("glFoo"));
}
static void
init(void)
{
glClearColor(0.4, 0.4, 0.4, 0.0);
if (0)
test_query_matrix();
}
static void
special_key(int special)
{
switch (special) {
case EGLUT_KEY_LEFT:
view_roty += 5.0;
break;
case EGLUT_KEY_RIGHT:
view_roty -= 5.0;
break;
case EGLUT_KEY_UP:
view_rotx += 5.0;
break;
case EGLUT_KEY_DOWN:
view_rotx -= 5.0;
break;
default:
break;
}
}
int
main(int argc, char *argv[])
{
eglutInitWindowSize(300, 300);
eglutInitAPIMask(EGLUT_OPENGL_ES1_BIT);
eglutInit(argc, argv);
eglutCreateWindow("tri");
eglutReshapeFunc(reshape);
eglutDisplayFunc(draw);
eglutSpecialFunc(special_key);
init();
eglutMainLoop();
return 0;
}
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