blob: 49b32253eed860a652cd19d6ae004a7ca5e93e1a [file] [log] [blame]
/**
* Test multi-texturing with GL shading language.
*
* 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.
*/
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <GL/glew.h>
#include "GL/glut.h"
#include "readtex.h"
#include "shaderutil.h"
static const char *Demo = "multitex";
static const char *VertFile = "multitex.vert";
static const char *FragFile = "multitex.frag";
static const char *TexFiles[2] =
{
"../images/tile.rgb",
"../images/tree2.rgba"
};
static GLuint Program;
static GLfloat Xrot = 0.0, Yrot = .0, Zrot = 0.0;
static GLfloat EyeDist = 10;
static GLboolean Anim = GL_TRUE;
static GLboolean UseArrays = GL_TRUE;
static GLboolean UseVBO = GL_TRUE;
static GLuint VBO = 0;
static GLint VertCoord_attr = -1, TexCoord0_attr = -1, TexCoord1_attr = -1;
/* value[0] = tex unit */
static struct uniform_info Uniforms[] = {
{ "tex1", 1, GL_SAMPLER_2D, { 0, 0, 0, 0 }, -1 },
{ "tex2", 1, GL_SAMPLER_2D, { 1, 0, 0, 0 }, -1 },
END_OF_UNIFORMS
};
static const GLfloat Tex0Coords[4][2] = {
{ 0.0, 0.0 }, { 2.0, 0.0 }, { 2.0, 2.0 }, { 0.0, 2.0 }
};
static const GLfloat Tex1Coords[4][2] = {
{ 0.0, 0.0 }, { 1.0, 0.0 }, { 1.0, 1.0 }, { 0.0, 1.0 }
};
static const GLfloat VertCoords[4][2] = {
{ -3.0, -3.0 }, { 3.0, -3.0 }, { 3.0, 3.0 }, { -3.0, 3.0 }
};
static void
SetupVertexBuffer(void)
{
glGenBuffersARB(1, &VBO);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
glBufferDataARB(GL_ARRAY_BUFFER_ARB,
sizeof(VertCoords) +
sizeof(Tex0Coords) +
sizeof(Tex1Coords),
NULL,
GL_STATIC_DRAW_ARB);
/* non-interleaved vertex arrays */
glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
0, /* offset */
sizeof(VertCoords), /* size */
VertCoords); /* data */
glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
sizeof(VertCoords), /* offset */
sizeof(Tex0Coords), /* size */
Tex0Coords); /* data */
glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
sizeof(VertCoords) +
sizeof(Tex0Coords), /* offset */
sizeof(Tex1Coords), /* size */
Tex1Coords); /* data */
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
static void
DrawPolygonArray(void)
{
void *vertPtr, *tex0Ptr, *tex1Ptr;
if (UseVBO) {
glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
vertPtr = (void *) 0;
tex0Ptr = (void *) sizeof(VertCoords);
tex1Ptr = (void *) (sizeof(VertCoords) + sizeof(Tex0Coords));
}
else {
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
vertPtr = VertCoords;
tex0Ptr = Tex0Coords;
tex1Ptr = Tex1Coords;
}
if (VertCoord_attr >= 0) {
glVertexAttribPointer(VertCoord_attr, 2, GL_FLOAT, GL_FALSE,
0, vertPtr);
glEnableVertexAttribArray(VertCoord_attr);
}
else {
glVertexPointer(2, GL_FLOAT, 0, vertPtr);
glEnableClientState(GL_VERTEX_ARRAY);
}
glVertexAttribPointer(TexCoord0_attr, 2, GL_FLOAT, GL_FALSE,
0, tex0Ptr);
glEnableVertexAttribArray(TexCoord0_attr);
glVertexAttribPointer(TexCoord1_attr, 2, GL_FLOAT, GL_FALSE,
0, tex1Ptr);
glEnableVertexAttribArray(TexCoord1_attr);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
static void
DrawPolygonVert(void)
{
GLuint i;
glBegin(GL_TRIANGLE_FAN);
for (i = 0; i < 4; i++) {
glVertexAttrib2fv(TexCoord0_attr, Tex0Coords[i]);
glVertexAttrib2fv(TexCoord1_attr, Tex1Coords[i]);
if (VertCoord_attr >= 0)
glVertexAttrib2fv(VertCoord_attr, VertCoords[i]);
else
glVertex2fv(VertCoords[i]);
}
glEnd();
}
static void
draw(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix(); /* modelview matrix */
glTranslatef(0.0, 0.0, -EyeDist);
glRotatef(Zrot, 0, 0, 1);
glRotatef(Yrot, 0, 1, 0);
glRotatef(Xrot, 1, 0, 0);
if (UseArrays)
DrawPolygonArray();
else
DrawPolygonVert();
glPopMatrix();
glutSwapBuffers();
}
static void
idle(void)
{
GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
Yrot = t;
glutPostRedisplay();
}
static void
key(unsigned char k, int x, int y)
{
(void) x;
(void) y;
switch (k) {
case 'a':
UseArrays = !UseArrays;
printf("Arrays: %d\n", UseArrays);
break;
case 'v':
UseVBO = !UseVBO;
printf("Use VBO: %d\n", UseVBO);
break;
case ' ':
Anim = !Anim;
if (Anim)
glutIdleFunc(idle);
else
glutIdleFunc(NULL);
break;
case 'z':
EyeDist -= 0.5;
if (EyeDist < 3.0)
EyeDist = 3.0;
break;
case 'Z':
EyeDist += 0.5;
if (EyeDist > 90.0)
EyeDist = 90;
break;
case 27:
exit(0);
}
glutPostRedisplay();
}
static void
specialkey(int key, int x, int y)
{
GLfloat step = 2.0;
(void) x;
(void) y;
switch (key) {
case GLUT_KEY_UP:
Xrot += step;
break;
case GLUT_KEY_DOWN:
Xrot -= step;
break;
case GLUT_KEY_LEFT:
Yrot -= step;
break;
case GLUT_KEY_RIGHT:
Yrot += step;
break;
}
glutPostRedisplay();
}
/* new window size or exposure */
static void
Reshape(int width, int height)
{
GLfloat ar = (float) width / (float) height;
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
static void
InitTextures(void)
{
GLenum filter = GL_LINEAR;
int i;
for (i = 0; i < 2; i++) {
GLint imgWidth, imgHeight;
GLenum imgFormat;
GLubyte *image = NULL;
image = LoadRGBImage(TexFiles[i], &imgWidth, &imgHeight, &imgFormat);
if (!image) {
printf("Couldn't read %s\n", TexFiles[i]);
exit(0);
}
glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(GL_TEXTURE_2D, 42 + i);
gluBuild2DMipmaps(GL_TEXTURE_2D, 4, imgWidth, imgHeight,
imgFormat, GL_UNSIGNED_BYTE, image);
free(image);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
}
}
static GLuint
CreateProgram(const char *vertProgFile, const char *fragProgFile,
struct uniform_info *uniforms)
{
GLuint fragShader, vertShader, program;
vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
assert(vertShader);
program = LinkShaders(vertShader, fragShader);
glUseProgram(program);
SetUniformValues(program, uniforms);
PrintUniforms(Uniforms);
assert(ValidateShaderProgram(program));
VertCoord_attr = glGetAttribLocation(program, "VertCoord");
if (VertCoord_attr > 0) {
/* We want the VertCoord attrib to have position zero so that
* the call to glVertexAttrib(0, xyz) triggers vertex processing.
* Otherwise, if TexCoord0 or TexCoord1 gets position 0 we'd have
* to set that attribute last (which is a PITA to manage).
*/
glBindAttribLocation(program, 0, "VertCoord");
/* re-link */
glLinkProgram(program);
/* VertCoord_attr should be zero now */
VertCoord_attr = glGetAttribLocation(program, "VertCoord");
assert(VertCoord_attr == 0);
}
TexCoord0_attr = glGetAttribLocation(program, "TexCoord0");
TexCoord1_attr = glGetAttribLocation(program, "TexCoord1");
printf("TexCoord0_attr = %d\n", TexCoord0_attr);
printf("TexCoord1_attr = %d\n", TexCoord1_attr);
printf("VertCoord_attr = %d\n", VertCoord_attr);
return program;
}
static void
InitPrograms(void)
{
Program = CreateProgram(VertFile, FragFile, Uniforms);
}
static void
InitGL(void)
{
if (!ShadersSupported())
exit(1);
printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
printf("Usage:\n");
printf(" a - toggle arrays vs. immediate mode rendering\n");
printf(" v - toggle VBO usage for array rendering\n");
printf(" z/Z - change viewing distance\n");
printf(" SPACE - toggle animation\n");
printf(" Esc - exit\n");
InitTextures();
InitPrograms();
SetupVertexBuffer();
glEnable(GL_DEPTH_TEST);
glClearColor(.6, .6, .9, 0);
glColor3f(1.0, 1.0, 1.0);
}
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitWindowSize(500, 400);
glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
glutCreateWindow(Demo);
glewInit();
glutReshapeFunc(Reshape);
glutKeyboardFunc(key);
glutSpecialFunc(specialkey);
glutDisplayFunc(draw);
if (Anim)
glutIdleFunc(idle);
InitGL();
glutMainLoop();
return 0;
}