mirror of
https://gitlab.freedesktop.org/mesa/mesa.git
synced 2026-01-03 18:00:10 +01:00
Test GL_VERTEX_PROGRAM_TWO_SIDE and frag shader gl_FrontFacing features
This commit is contained in:
Brian
parent
caec2a79e6
commit
87002aba3b
1 changed files with 348 additions and 0 deletions
348
progs/glsl/twoside.c
Normal file
348
progs/glsl/twoside.c
Normal file
|
|
@ -0,0 +1,348 @@
|
|||
/**
|
||||
* Test two-sided lighting with shaders.
|
||||
* Both GL_VERTEX_PROGRAM_TWO_SIDE and gl_FrontFacing can be tested
|
||||
* (see keys below).
|
||||
*
|
||||
* Brian Paul
|
||||
* 18 Dec 2007
|
||||
*/
|
||||
|
||||
#include <assert.h>
|
||||
#include <string.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <math.h>
|
||||
#include <GL/gl.h>
|
||||
#include <GL/glut.h>
|
||||
#include <GL/glext.h>
|
||||
#include "extfuncs.h"
|
||||
|
||||
|
||||
static const char *Prog = "twoside";
|
||||
static GLint WinWidth = 300, WinHeight = 300;
|
||||
static char *FragProgFile = NULL;
|
||||
static char *VertProgFile = NULL;
|
||||
static GLuint fragShader;
|
||||
static GLuint vertShader;
|
||||
static GLuint program;
|
||||
static GLint win = 0;
|
||||
static GLboolean anim = 0*GL_TRUE;
|
||||
static GLboolean DetermineInFragProg = GL_TRUE;
|
||||
static GLfloat Yrot = 0.0f;
|
||||
static GLint u_fragface;
|
||||
static GLenum FrontWinding = GL_CCW;
|
||||
static int prevTime = 0;
|
||||
|
||||
|
||||
static const GLfloat Red[4] = {1, 0, 0, 0};
|
||||
static const GLfloat Green[4] = {0, 1, 0, 0};
|
||||
|
||||
|
||||
static void
|
||||
Redisplay(void)
|
||||
{
|
||||
float xmin = -1, xmax = 1, ymin = -1, ymax = 1;
|
||||
|
||||
glFrontFace(FrontWinding);
|
||||
|
||||
if (DetermineInFragProg) {
|
||||
glUniform1i_func(u_fragface, 1);
|
||||
glDisable(GL_VERTEX_PROGRAM_TWO_SIDE);
|
||||
}
|
||||
else {
|
||||
glUniform1i_func(u_fragface, 0);
|
||||
glEnable(GL_VERTEX_PROGRAM_TWO_SIDE);
|
||||
}
|
||||
|
||||
glClear(GL_COLOR_BUFFER_BIT);
|
||||
|
||||
glPushMatrix();
|
||||
glRotatef(Yrot, 0, 1, 0);
|
||||
|
||||
glBegin(GL_POLYGON);
|
||||
glColor4fv(Red);
|
||||
glSecondaryColor3fv_func(Green);
|
||||
glVertex2f(xmin, ymin);
|
||||
glVertex2f(xmax, ymin);
|
||||
glVertex2f(xmax, ymax);
|
||||
glVertex2f(xmin, ymax);
|
||||
glEnd();
|
||||
|
||||
glPopMatrix();
|
||||
|
||||
glutSwapBuffers();
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
Idle(void)
|
||||
{
|
||||
int curTime = glutGet(GLUT_ELAPSED_TIME);
|
||||
int dt = curTime - prevTime;
|
||||
|
||||
if (prevTime == 0) {
|
||||
prevTime = curTime;
|
||||
return;
|
||||
}
|
||||
prevTime = curTime;
|
||||
|
||||
Yrot += dt * 0.1;
|
||||
glutPostRedisplay();
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
Reshape(int width, int height)
|
||||
{
|
||||
float ar = (float) width / height;
|
||||
glViewport(0, 0, width, height);
|
||||
glMatrixMode(GL_PROJECTION);
|
||||
glLoadIdentity();
|
||||
glFrustum(-ar, ar, -1, 1, 5, 15);
|
||||
glMatrixMode(GL_MODELVIEW);
|
||||
glLoadIdentity();
|
||||
glTranslatef(0, 0, -10);
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
CleanUp(void)
|
||||
{
|
||||
glDeleteShader_func(fragShader);
|
||||
glDeleteShader_func(vertShader);
|
||||
glDeleteProgram_func(program);
|
||||
glutDestroyWindow(win);
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
Key(unsigned char key, int x, int y)
|
||||
{
|
||||
(void) x;
|
||||
(void) y;
|
||||
|
||||
switch(key) {
|
||||
case ' ':
|
||||
case 'a':
|
||||
anim = !anim;
|
||||
if (anim) {
|
||||
prevTime = glutGet(GLUT_ELAPSED_TIME);
|
||||
glutIdleFunc(Idle);
|
||||
}
|
||||
else
|
||||
glutIdleFunc(NULL);
|
||||
break;
|
||||
case 'f':
|
||||
printf("Using frag shader gl_FrontFacing\n");
|
||||
DetermineInFragProg = GL_TRUE;
|
||||
break;
|
||||
case 'v':
|
||||
printf("Using vert shader Two-sided lighting\n");
|
||||
DetermineInFragProg = GL_FALSE;
|
||||
break;
|
||||
case 'r':
|
||||
Yrot = 0;
|
||||
anim = 0;
|
||||
glutIdleFunc(NULL);
|
||||
break;
|
||||
case 's':
|
||||
Yrot += 5;
|
||||
break;
|
||||
case 'w':
|
||||
if (FrontWinding == GL_CCW) {
|
||||
FrontWinding = GL_CW;
|
||||
printf("FrontFace = GL_CW\n");
|
||||
}
|
||||
else {
|
||||
FrontWinding = GL_CCW;
|
||||
printf("FrontFace = GL_CCW\n");
|
||||
}
|
||||
break;
|
||||
case 27:
|
||||
CleanUp();
|
||||
exit(0);
|
||||
break;
|
||||
}
|
||||
glutPostRedisplay();
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
LoadAndCompileShader(GLuint shader, const char *text)
|
||||
{
|
||||
GLint stat;
|
||||
|
||||
glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
|
||||
|
||||
glCompileShader_func(shader);
|
||||
|
||||
glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
|
||||
if (!stat) {
|
||||
GLchar log[1000];
|
||||
GLsizei len;
|
||||
glGetShaderInfoLog_func(shader, 1000, &len, log);
|
||||
fprintf(stderr, "%s: problem compiling shader:\n%s\n", Prog, log);
|
||||
exit(1);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Read a shader from a file.
|
||||
*/
|
||||
static void
|
||||
ReadShader(GLuint shader, const char *filename)
|
||||
{
|
||||
const int max = 100*1000;
|
||||
int n;
|
||||
char *buffer = (char*) malloc(max);
|
||||
FILE *f = fopen(filename, "r");
|
||||
if (!f) {
|
||||
fprintf(stderr, "%s: Unable to open shader file %s\n", Prog, filename);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
n = fread(buffer, 1, max, f);
|
||||
printf("%s: read %d bytes from shader file %s\n", Prog, n, filename);
|
||||
if (n > 0) {
|
||||
buffer[n] = 0;
|
||||
LoadAndCompileShader(shader, buffer);
|
||||
}
|
||||
|
||||
fclose(f);
|
||||
free(buffer);
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
CheckLink(GLuint prog)
|
||||
{
|
||||
GLint stat;
|
||||
glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
|
||||
if (!stat) {
|
||||
GLchar log[1000];
|
||||
GLsizei len;
|
||||
glGetProgramInfoLog_func(prog, 1000, &len, log);
|
||||
fprintf(stderr, "Linker error:\n%s\n", log);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
Init(void)
|
||||
{
|
||||
static const char *fragShaderText =
|
||||
"uniform bool fragface; \n"
|
||||
"void main() { \n"
|
||||
" if (!fragface || gl_FrontFacing) { \n"
|
||||
" gl_FragColor = gl_Color; \n"
|
||||
" } \n"
|
||||
" else { \n"
|
||||
" gl_FragColor = 0.8 * gl_SecondaryColor; \n"
|
||||
" } \n"
|
||||
"} \n";
|
||||
static const char *vertShaderText =
|
||||
"uniform bool fragface; \n"
|
||||
"void main() { \n"
|
||||
" gl_FrontColor = gl_Color; \n"
|
||||
" if (fragface) { \n"
|
||||
" // front/back chosen in frag prog \n"
|
||||
" gl_FrontSecondaryColor = gl_SecondaryColor; \n"
|
||||
" } \n"
|
||||
" else { \n"
|
||||
" // front/back chosen in prim setup \n"
|
||||
" gl_BackColor = gl_SecondaryColor; \n"
|
||||
" } \n"
|
||||
" gl_Position = ftransform(); \n"
|
||||
"} \n";
|
||||
const char *version;
|
||||
|
||||
version = (const char *) glGetString(GL_VERSION);
|
||||
if (version[0] != '2' || version[1] != '.') {
|
||||
printf("This program requires OpenGL 2.x, found %s\n", version);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
GetExtensionFuncs();
|
||||
|
||||
fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
|
||||
if (FragProgFile)
|
||||
ReadShader(fragShader, FragProgFile);
|
||||
else
|
||||
LoadAndCompileShader(fragShader, fragShaderText);
|
||||
|
||||
vertShader = glCreateShader_func(GL_VERTEX_SHADER);
|
||||
if (VertProgFile)
|
||||
ReadShader(vertShader, VertProgFile);
|
||||
else
|
||||
LoadAndCompileShader(vertShader, vertShaderText);
|
||||
|
||||
program = glCreateProgram_func();
|
||||
glAttachShader_func(program, fragShader);
|
||||
glAttachShader_func(program, vertShader);
|
||||
glLinkProgram_func(program);
|
||||
CheckLink(program);
|
||||
glUseProgram_func(program);
|
||||
|
||||
u_fragface = glGetUniformLocation_func(program, "fragface");
|
||||
printf("Uniforms: %d\n", u_fragface);
|
||||
|
||||
/*assert(glGetError() == 0);*/
|
||||
|
||||
glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
|
||||
|
||||
printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
|
||||
|
||||
assert(glIsProgram_func(program));
|
||||
assert(glIsShader_func(fragShader));
|
||||
assert(glIsShader_func(vertShader));
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
ParseOptions(int argc, char *argv[])
|
||||
{
|
||||
int i;
|
||||
for (i = 1; i < argc; i++) {
|
||||
if (strcmp(argv[i], "-fs") == 0) {
|
||||
FragProgFile = argv[i+1];
|
||||
}
|
||||
else if (strcmp(argv[i], "-vs") == 0) {
|
||||
VertProgFile = argv[i+1];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
Usage(void)
|
||||
{
|
||||
printf("Keys:\n");
|
||||
printf(" f - do front/back determination in fragment shader\n");
|
||||
printf(" v - do front/back determination in vertex shader\n");
|
||||
printf(" r - reset, show front\n");
|
||||
printf(" a - toggle animation\n");
|
||||
printf(" s - step rotation\n");
|
||||
printf(" w - toggle CW, CCW front-face winding\n");
|
||||
}
|
||||
|
||||
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
glutInit(&argc, argv);
|
||||
glutInitWindowPosition( 0, 0);
|
||||
glutInitWindowSize(WinWidth, WinHeight);
|
||||
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
|
||||
win = glutCreateWindow(argv[0]);
|
||||
glutReshapeFunc(Reshape);
|
||||
glutKeyboardFunc(Key);
|
||||
glutDisplayFunc(Redisplay);
|
||||
if (anim)
|
||||
glutIdleFunc(Idle);
|
||||
ParseOptions(argc, argv);
|
||||
Init();
|
||||
Usage();
|
||||
glutMainLoop();
|
||||
return 0;
|
||||
}
|
||||
Loading…
Add table
Reference in a new issue