progs/es1: Port eglgears to OpenGL ES 1.1.
This demo requires EGL_MESA_screen_surface to run. Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
This commit is contained in:
Chia-I Wu
Brian Paul
parent
381cbc7192
commit
b30876658b
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@ -1,3 +1,4 @@
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screen/gears
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screen/tri
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xegl/drawtex
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xegl/es1_info
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@ -13,6 +13,7 @@ ES1_LIB_DEPS = \
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WINSYS_OBJS = winsys.o
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PROGRAMS = \
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gears \
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tri
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.c.o:
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@ -20,6 +21,9 @@ PROGRAMS = \
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default: $(PROGRAMS)
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gears: gears.o $(WINSYS_OBJS) $(ES1_LIB_DEPS)
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$(CC) $(CFLAGS) -o $@ $@.o $(WINSYS_OBJS) $(ES1_LIBS)
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tri: tri.o $(WINSYS_OBJS) $(ES1_LIB_DEPS)
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$(CC) $(CFLAGS) -o $@ $@.o $(WINSYS_OBJS) $(ES1_LIBS)
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@ -0,0 +1,374 @@
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/*
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* Copyright (C) 2009 Chia-I Wu <olv@0xlab.org>
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*
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* Based on eglgears by
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* Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <math.h>
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#include <assert.h>
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#include <GLES/gl.h>
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#include "winsys.h"
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#ifndef M_PI
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#define M_PI 3.14159265
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#endif
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struct gear {
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GLuint vbo;
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GLfloat *vertices;
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GLsizei stride;
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GLint num_teeth;
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};
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static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
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static struct gear gears[3];
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static GLfloat angle = 0.0;
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/*
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* Initialize a gear wheel.
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*
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* Input: gear - gear to initialize
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* inner_radius - radius of hole at center
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* outer_radius - radius at center of teeth
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* width - width of gear
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* teeth - number of teeth
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* tooth_depth - depth of tooth
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*/
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static void
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init_gear(struct gear *gear, GLfloat inner_radius, GLfloat outer_radius,
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GLfloat width, GLint teeth, GLfloat tooth_depth)
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{
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GLfloat r0, r1, r2;
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GLfloat a0, da;
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GLint verts_per_tooth, total_verts, total_size;
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GLint count, i;
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GLfloat *verts;
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r0 = inner_radius;
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r1 = outer_radius - tooth_depth / 2.0;
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r2 = outer_radius + tooth_depth / 2.0;
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a0 = 2.0 * M_PI / teeth;
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da = a0 / 4.0;
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gear->vbo = 0;
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gear->vertices = NULL;
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gear->stride = sizeof(GLfloat) * 6; /* XYZ + normal */
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gear->num_teeth = teeth;
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verts_per_tooth = 10 + 4;
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total_verts = teeth * verts_per_tooth;
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total_size = total_verts * gear->stride;
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verts = malloc(total_size);
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if (!verts) {
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printf("failed to allocate vertices\n");
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return;
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}
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#define GEAR_VERT(r, n, sign) \
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do { \
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verts[count * 6 + 0] = (r) * vx[n]; \
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verts[count * 6 + 1] = (r) * vy[n]; \
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verts[count * 6 + 2] = (sign) * width * 0.5; \
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verts[count * 6 + 3] = normal[0]; \
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verts[count * 6 + 4] = normal[1]; \
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verts[count * 6 + 5] = normal[2]; \
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count++; \
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} while (0)
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count = 0;
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for (i = 0; i < teeth; i++) {
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GLfloat normal[3];
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GLfloat vx[5], vy[5];
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GLfloat u, v;
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normal[0] = 0.0;
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normal[1] = 0.0;
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normal[2] = 0.0;
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vx[0] = cos(i * a0 + 0 * da);
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vy[0] = sin(i * a0 + 0 * da);
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vx[1] = cos(i * a0 + 1 * da);
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vy[1] = sin(i * a0 + 1 * da);
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vx[2] = cos(i * a0 + 2 * da);
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vy[2] = sin(i * a0 + 2 * da);
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vx[3] = cos(i * a0 + 3 * da);
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vy[3] = sin(i * a0 + 3 * da);
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vx[4] = cos(i * a0 + 4 * da);
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vy[4] = sin(i * a0 + 4 * da);
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/* outward faces of a tooth, 10 verts */
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normal[0] = vx[0];
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normal[1] = vy[0];
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GEAR_VERT(r1, 0, 1);
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GEAR_VERT(r1, 0, -1);
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u = r2 * vx[1] - r1 * vx[0];
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v = r2 * vy[1] - r1 * vy[0];
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normal[0] = v;
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normal[1] = -u;
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GEAR_VERT(r2, 1, 1);
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GEAR_VERT(r2, 1, -1);
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normal[0] = vx[0];
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normal[1] = vy[0];
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GEAR_VERT(r2, 2, 1);
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GEAR_VERT(r2, 2, -1);
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u = r1 * vx[3] - r2 * vx[2];
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v = r1 * vy[3] - r2 * vy[2];
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normal[0] = v;
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normal[1] = -u;
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GEAR_VERT(r1, 3, 1);
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GEAR_VERT(r1, 3, -1);
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normal[0] = vx[0];
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normal[1] = vy[0];
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GEAR_VERT(r1, 4, 1);
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GEAR_VERT(r1, 4, -1);
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/* inside radius cylinder, 4 verts */
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normal[0] = -vx[4];
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normal[1] = -vy[4];
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GEAR_VERT(r0, 4, 1);
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GEAR_VERT(r0, 4, -1);
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normal[0] = -vx[0];
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normal[1] = -vy[0];
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GEAR_VERT(r0, 0, 1);
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GEAR_VERT(r0, 0, -1);
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assert(count % verts_per_tooth == 0);
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}
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assert(count == total_verts);
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#undef GEAR_VERT
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gear->vertices = verts;
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/* setup VBO */
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glGenBuffers(1, &gear->vbo);
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if (gear->vbo) {
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glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
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glBufferData(GL_ARRAY_BUFFER, total_size, verts, GL_STATIC_DRAW);
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}
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}
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static void
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draw_gear(const struct gear *gear)
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{
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GLint i;
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if (!gear->vbo && !gear->vertices) {
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printf("nothing to be drawn\n");
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return;
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}
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if (gear->vbo) {
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glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
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glVertexPointer(3, GL_FLOAT, gear->stride, (const GLvoid *) 0);
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glNormalPointer(GL_FLOAT, gear->stride, (const GLvoid *) (sizeof(GLfloat) * 3));
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} else {
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glBindBuffer(GL_ARRAY_BUFFER, 0);
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glVertexPointer(3, GL_FLOAT, gear->stride, gear->vertices);
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glNormalPointer(GL_FLOAT, gear->stride, gear->vertices + 3);
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}
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glEnableClientState(GL_VERTEX_ARRAY);
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for (i = 0; i < gear->num_teeth; i++) {
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const GLint base = (10 + 4) * i;
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GLushort indices[7];
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glShadeModel(GL_FLAT);
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/* front face */
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indices[0] = base + 12;
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indices[1] = base + 0;
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indices[2] = base + 2;
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indices[3] = base + 4;
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indices[4] = base + 6;
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indices[5] = base + 8;
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indices[6] = base + 10;
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glNormal3f(0.0, 0.0, 1.0);
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glDrawElements(GL_TRIANGLE_FAN, 7, GL_UNSIGNED_SHORT, indices);
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/* back face */
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indices[0] = base + 13;
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indices[1] = base + 11;
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indices[2] = base + 9;
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indices[3] = base + 7;
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indices[4] = base + 5;
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indices[5] = base + 3;
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indices[6] = base + 1;
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glNormal3f(0.0, 0.0, -1.0);
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glDrawElements(GL_TRIANGLE_FAN, 7, GL_UNSIGNED_SHORT, indices);
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glEnableClientState(GL_NORMAL_ARRAY);
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/* outward face of a tooth */
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glDrawArrays(GL_TRIANGLE_STRIP, base, 10);
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/* inside radius cylinder */
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glShadeModel(GL_SMOOTH);
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glDrawArrays(GL_TRIANGLE_STRIP, base + 10, 4);
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glDisableClientState(GL_NORMAL_ARRAY);
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}
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glDisableClientState(GL_VERTEX_ARRAY);
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}
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static void
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gears_draw(void *data)
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{
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static const GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
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static const GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
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static const GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
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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, 0.0, 0.0);
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glRotatef(view_roty, 0.0, 1.0, 0.0);
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glRotatef(view_rotz, 0.0, 0.0, 1.0);
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glPushMatrix();
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glTranslatef(-3.0, -2.0, 0.0);
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glRotatef(angle, 0.0, 0.0, 1.0);
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glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red);
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draw_gear(&gears[0]);
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glPopMatrix();
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glPushMatrix();
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glTranslatef(3.1, -2.0, 0.0);
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glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
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glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green);
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draw_gear(&gears[1]);
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glPopMatrix();
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glPushMatrix();
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glTranslatef(-3.1, 4.2, 0.0);
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glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
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glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue);
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draw_gear(&gears[2]);
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glPopMatrix();
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glPopMatrix();
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/* advance rotation for next frame */
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angle += 0.5; /* 0.5 degree per frame */
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if (angle > 3600.0)
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angle -= 3600.0;
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}
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static void gears_fini(void)
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{
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GLint i;
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for (i = 0; i < 3; i++) {
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struct gear *gear = &gears[i];
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if (gear->vbo) {
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glDeleteBuffers(1, &gear->vbo);
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gear->vbo = 0;
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}
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if (gear->vertices) {
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free(gear->vertices);
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gear->vertices = NULL;
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}
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}
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}
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static void gears_init(void)
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{
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static const GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
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glLightfv(GL_LIGHT0, GL_POSITION, pos);
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glEnable(GL_CULL_FACE);
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glEnable(GL_LIGHTING);
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glEnable(GL_LIGHT0);
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glEnable(GL_DEPTH_TEST);
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glEnable(GL_NORMALIZE);
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init_gear(&gears[0], 1.0, 4.0, 1.0, 20, 0.7);
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init_gear(&gears[1], 0.5, 2.0, 2.0, 10, 0.7);
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init_gear(&gears[2], 1.3, 2.0, 0.5, 10, 0.7);
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}
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/* new window size or exposure */
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static void
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gears_reshape(int width, int height)
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{
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GLfloat h = (GLfloat) height / (GLfloat) width;
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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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glFrustumf(-1.0, 1.0, -h, h, 5.0, 60.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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glTranslatef(0.0, 0.0, -40.0);
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}
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static void gears_run(void)
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{
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winsysRun(5.0, gears_draw, NULL);
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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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EGLint width, height;
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if (!winsysInitScreen())
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exit(1);
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winsysQueryScreenSize(&width, &height);
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gears_init();
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gears_reshape(width, height);
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gears_run();
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gears_fini();
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winsysFiniScreen();
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return 0;
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}
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