449 lines
11 KiB
C
449 lines
11 KiB
C
/*
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* Copyright (C) 2008 Tunsgten Graphics,Inc. All Rights Reserved.
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*/
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/*
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* Draw a lit, textured torus with X/EGL and OpenGL ES 1.x
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* Brian Paul
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* July 2008
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*/
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#include <assert.h>
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#include <math.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <GLES/gl.h>
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#include "eglut.h"
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static const struct {
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GLenum internalFormat;
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const char *name;
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GLuint num_entries;
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GLuint size;
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} cpal_formats[] = {
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{ GL_PALETTE4_RGB8_OES, "GL_PALETTE4_RGB8_OES", 16, 3 },
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{ GL_PALETTE4_RGBA8_OES, "GL_PALETTE4_RGBA8_OES", 16, 4 },
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{ GL_PALETTE4_R5_G6_B5_OES, "GL_PALETTE4_R5_G6_B5_OES", 16, 2 },
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{ GL_PALETTE4_RGBA4_OES, "GL_PALETTE4_RGBA4_OES", 16, 2 },
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{ GL_PALETTE4_RGB5_A1_OES, "GL_PALETTE4_RGB5_A1_OES", 16, 2 },
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{ GL_PALETTE8_RGB8_OES, "GL_PALETTE8_RGB8_OES", 256, 3 },
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{ GL_PALETTE8_RGBA8_OES, "GL_PALETTE8_RGBA8_OES", 256, 4 },
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{ GL_PALETTE8_R5_G6_B5_OES, "GL_PALETTE8_R5_G6_B5_OES", 256, 2 },
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{ GL_PALETTE8_RGBA4_OES, "GL_PALETTE8_RGBA4_OES", 256, 2 },
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{ GL_PALETTE8_RGB5_A1_OES, "GL_PALETTE8_RGB5_A1_OES", 256, 2 }
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};
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#define NUM_CPAL_FORMATS (sizeof(cpal_formats) / sizeof(cpal_formats[0]))
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static GLfloat view_rotx = 0.0, view_roty = 0.0, view_rotz = 0.0;
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static GLint tex_format = NUM_CPAL_FORMATS;
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static GLboolean animate = GL_TRUE;
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static int win;
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static void
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Normal(GLfloat *n, GLfloat nx, GLfloat ny, GLfloat nz)
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{
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n[0] = nx;
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n[1] = ny;
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n[2] = nz;
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}
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static void
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Vertex(GLfloat *v, GLfloat vx, GLfloat vy, GLfloat vz)
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{
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v[0] = vx;
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v[1] = vy;
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v[2] = vz;
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}
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static void
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Texcoord(GLfloat *v, GLfloat s, GLfloat t)
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{
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v[0] = s;
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v[1] = t;
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}
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/* Borrowed from glut, adapted */
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static void
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draw_torus(GLfloat r, GLfloat R, GLint nsides, GLint rings)
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{
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int i, j;
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GLfloat theta, phi, theta1;
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GLfloat cosTheta, sinTheta;
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GLfloat cosTheta1, sinTheta1;
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GLfloat ringDelta, sideDelta;
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GLfloat varray[100][3], narray[100][3], tarray[100][2];
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int vcount;
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glVertexPointer(3, GL_FLOAT, 0, varray);
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glNormalPointer(GL_FLOAT, 0, narray);
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glTexCoordPointer(2, GL_FLOAT, 0, tarray);
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glEnableClientState(GL_VERTEX_ARRAY);
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glEnableClientState(GL_NORMAL_ARRAY);
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glEnableClientState(GL_TEXTURE_COORD_ARRAY);
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ringDelta = 2.0 * M_PI / rings;
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sideDelta = 2.0 * M_PI / nsides;
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theta = 0.0;
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cosTheta = 1.0;
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sinTheta = 0.0;
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for (i = rings - 1; i >= 0; i--) {
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theta1 = theta + ringDelta;
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cosTheta1 = cos(theta1);
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sinTheta1 = sin(theta1);
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vcount = 0; /* glBegin(GL_QUAD_STRIP); */
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phi = 0.0;
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for (j = nsides; j >= 0; j--) {
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GLfloat s0, s1, t;
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GLfloat cosPhi, sinPhi, dist;
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phi += sideDelta;
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cosPhi = cos(phi);
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sinPhi = sin(phi);
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dist = R + r * cosPhi;
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s0 = 20.0 * theta / (2.0 * M_PI);
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s1 = 20.0 * theta1 / (2.0 * M_PI);
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t = 8.0 * phi / (2.0 * M_PI);
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Normal(narray[vcount], cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
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Texcoord(tarray[vcount], s1, t);
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Vertex(varray[vcount], cosTheta1 * dist, -sinTheta1 * dist, r * sinPhi);
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vcount++;
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Normal(narray[vcount], cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
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Texcoord(tarray[vcount], s0, t);
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Vertex(varray[vcount], cosTheta * dist, -sinTheta * dist, r * sinPhi);
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vcount++;
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}
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/*glEnd();*/
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assert(vcount <= 100);
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glDrawArrays(GL_TRIANGLE_STRIP, 0, vcount);
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theta = theta1;
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cosTheta = cosTheta1;
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sinTheta = sinTheta1;
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}
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glDisableClientState(GL_VERTEX_ARRAY);
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glDisableClientState(GL_NORMAL_ARRAY);
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glDisableClientState(GL_TEXTURE_COORD_ARRAY);
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}
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static void
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draw(void)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glPushMatrix();
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glRotatef(view_rotx, 1, 0, 0);
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glRotatef(view_roty, 0, 1, 0);
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glRotatef(view_rotz, 0, 0, 1);
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glScalef(0.5, 0.5, 0.5);
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draw_torus(1.0, 3.0, 30, 60);
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glPopMatrix();
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}
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/* new window size or exposure */
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static void
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reshape(int width, int height)
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{
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GLfloat ar = (GLfloat) width / (GLfloat) height;
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glViewport(0, 0, (GLint) width, (GLint) height);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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#ifdef GL_VERSION_ES_CM_1_0
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glFrustumf(-ar, ar, -1, 1, 5.0, 60.0);
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#else
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glFrustum(-ar, ar, -1, 1, 5.0, 60.0);
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#endif
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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glTranslatef(0.0, 0.0, -15.0);
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}
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static GLint
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make_cpal_texture(GLint idx)
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{
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#define SZ 64
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GLenum internalFormat = GL_PALETTE4_RGB8_OES + idx;
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GLenum Filter = GL_LINEAR;
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GLubyte palette[256 * 4 + SZ * SZ];
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GLubyte *indices;
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GLsizei image_size;
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GLuint i, j;
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GLuint packed_indices = 0;
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assert(cpal_formats[idx].internalFormat == internalFormat);
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/* init palette */
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switch (internalFormat) {
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case GL_PALETTE4_RGB8_OES:
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case GL_PALETTE8_RGB8_OES:
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/* first entry */
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palette[0] = 255;
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palette[1] = 255;
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palette[2] = 255;
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/* second entry */
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palette[3] = 127;
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palette[4] = 127;
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palette[5] = 127;
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break;
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case GL_PALETTE4_RGBA8_OES:
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case GL_PALETTE8_RGBA8_OES:
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/* first entry */
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palette[0] = 255;
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palette[1] = 255;
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palette[2] = 255;
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palette[3] = 255;
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/* second entry */
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palette[4] = 127;
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palette[5] = 127;
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palette[6] = 127;
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palette[7] = 255;
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break;
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case GL_PALETTE4_R5_G6_B5_OES:
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case GL_PALETTE8_R5_G6_B5_OES:
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{
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GLushort *pal = (GLushort *) palette;
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/* first entry */
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pal[0] = (31 << 11 | 63 << 5 | 31);
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/* second entry */
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pal[1] = (15 << 11 | 31 << 5 | 15);
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}
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break;
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case GL_PALETTE4_RGBA4_OES:
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case GL_PALETTE8_RGBA4_OES:
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{
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GLushort *pal = (GLushort *) palette;
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/* first entry */
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pal[0] = (15 << 12 | 15 << 8 | 15 << 4 | 15);
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/* second entry */
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pal[1] = (7 << 12 | 7 << 8 | 7 << 4 | 15);
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}
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break;
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case GL_PALETTE4_RGB5_A1_OES:
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case GL_PALETTE8_RGB5_A1_OES:
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{
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GLushort *pal = (GLushort *) palette;
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/* first entry */
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pal[0] = (31 << 11 | 31 << 6 | 31 << 1 | 1);
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/* second entry */
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pal[1] = (15 << 11 | 15 << 6 | 15 << 1 | 1);
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}
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break;
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}
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image_size = cpal_formats[idx].size * cpal_formats[idx].num_entries;
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indices = palette + image_size;
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for (i = 0; i < SZ; i++) {
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for (j = 0; j < SZ; j++) {
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GLfloat d;
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GLint index;
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d = (i - SZ/2) * (i - SZ/2) + (j - SZ/2) * (j - SZ/2);
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d = sqrt(d);
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index = (d < SZ / 3) ? 0 : 1;
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if (cpal_formats[idx].num_entries == 16) {
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/* 4-bit indices packed in GLubyte */
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packed_indices |= index << (4 * (1 - (j % 2)));
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if (j % 2) {
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*(indices + (i * SZ + j - 1) / 2) = packed_indices & 0xff;
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packed_indices = 0;
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image_size += 1;
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}
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}
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else {
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/* 8-bit indices */
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*(indices + i * SZ + j) = index;
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image_size += 1;
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}
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}
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}
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glActiveTexture(GL_TEXTURE0); /* unit 0 */
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glBindTexture(GL_TEXTURE_2D, 42);
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glCompressedTexImage2D(GL_TEXTURE_2D, 0, internalFormat, SZ, SZ, 0,
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image_size, palette);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, Filter);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, Filter);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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#undef SZ
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return image_size;
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}
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static GLint
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make_texture(void)
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{
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#define SZ 64
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GLenum Filter = GL_LINEAR;
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GLubyte image[SZ][SZ][4];
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GLuint i, j;
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for (i = 0; i < SZ; i++) {
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for (j = 0; j < SZ; j++) {
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GLfloat d = (i - SZ/2) * (i - SZ/2) + (j - SZ/2) * (j - SZ/2);
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d = sqrt(d);
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if (d < SZ/3) {
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image[i][j][0] = 255;
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image[i][j][1] = 255;
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image[i][j][2] = 255;
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image[i][j][3] = 255;
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}
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else {
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image[i][j][0] = 127;
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image[i][j][1] = 127;
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image[i][j][2] = 127;
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image[i][j][3] = 255;
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}
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}
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}
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glActiveTexture(GL_TEXTURE0); /* unit 0 */
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glBindTexture(GL_TEXTURE_2D, 42);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SZ, SZ, 0,
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GL_RGBA, GL_UNSIGNED_BYTE, image);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, Filter);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, Filter);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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#undef SZ
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return sizeof(image);
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}
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static void
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init(void)
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{
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static const GLfloat red[4] = {1, 0, 0, 0};
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static const GLfloat white[4] = {1.0, 1.0, 1.0, 1.0};
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static const GLfloat diffuse[4] = {0.7, 0.7, 0.7, 1.0};
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static const GLfloat specular[4] = {0.001, 0.001, 0.001, 1.0};
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static const GLfloat pos[4] = {20, 20, 50, 1};
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glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red);
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glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, white);
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glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 9.0);
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glEnable(GL_LIGHTING);
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glEnable(GL_LIGHT0);
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glLightfv(GL_LIGHT0, GL_POSITION, pos);
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glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
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glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
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glClearColor(0.4, 0.4, 0.4, 0.0);
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glEnable(GL_DEPTH_TEST);
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make_texture();
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glEnable(GL_TEXTURE_2D);
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}
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static void
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idle(void)
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{
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if (animate) {
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view_rotx += 1.0;
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view_roty += 2.0;
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eglutPostRedisplay();
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}
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}
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static void
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key(unsigned char key)
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{
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switch (key) {
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case ' ':
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animate = !animate;
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break;
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case 't':
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{
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GLint size;
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tex_format = (tex_format + 1) % (NUM_CPAL_FORMATS + 1);
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if (tex_format < NUM_CPAL_FORMATS) {
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size = make_cpal_texture(tex_format);
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printf("Using %s (%d bytes)\n",
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cpal_formats[tex_format].name, size);
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}
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else {
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size = make_texture();
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printf("Using uncompressed texture (%d bytes)\n", size);
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}
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eglutPostRedisplay();
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}
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break;
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case 27:
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eglutDestroyWindow(win);
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exit(0);
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break;
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default:
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break;
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}
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}
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static void
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special_key(int key)
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{
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switch (key) {
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case EGLUT_KEY_LEFT:
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view_roty += 5.0;
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break;
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case EGLUT_KEY_RIGHT:
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view_roty -= 5.0;
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break;
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case EGLUT_KEY_UP:
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view_rotx += 5.0;
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break;
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case EGLUT_KEY_DOWN:
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view_rotx -= 5.0;
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break;
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default:
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break;
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}
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}
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int
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main(int argc, char *argv[])
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{
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eglutInitWindowSize(300, 300);
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eglutInitAPIMask(EGLUT_OPENGL_ES1_BIT);
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eglutInit(argc, argv);
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win = eglutCreateWindow("torus");
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eglutIdleFunc(idle);
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eglutReshapeFunc(reshape);
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eglutDisplayFunc(draw);
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eglutKeyboardFunc(key);
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eglutSpecialFunc(special_key);
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init();
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eglutMainLoop();
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return 0;
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}
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