1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define GL_GLEXT_PROTOTYPES
#include <GL/glut.h>
#include "readtex.c"
#define TEXTURE_FILE "../images/girl.rgb"
static void Init( void )
{
static const char *modulate2D =
"!!ARBfp1.0\n"
"TEX result.color, fragment.color, texture[0], 2D; \n"
"END"
;
GLuint modulateProg;
GLuint Texture;
if (!glutExtensionSupported("GL_ARB_fragment_program")) {
printf("Error: GL_ARB_fragment_program not supported!\n");
exit(1);
}
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
/* Setup the fragment program */
glGenProgramsARB(1, &modulateProg);
glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, modulateProg);
glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
strlen(modulate2D), (const GLubyte *)modulate2D);
printf("glGetError = 0x%x\n", (int) glGetError());
printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
(char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
assert(glIsProgramARB(modulateProg));
glEnable(GL_FRAGMENT_PROGRAM_ARB);
/* Load texture */
glGenTextures(1, &Texture);
glBindTexture(GL_TEXTURE_2D, Texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
printf("Error: couldn't load texture image file %s\n", TEXTURE_FILE);
exit(1);
}
/* XXX this enable shouldn't really be needed!!! */
glEnable(GL_TEXTURE_2D);
glClearColor(.3, .3, .3, 0);
}
static void Reshape(int width, int height)
{
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
glMatrixMode(GL_MODELVIEW);
}
static void Key(unsigned char key, int x, int y)
{
switch (key) {
case 27:
exit(1);
default:
return;
}
glutPostRedisplay();
}
static void Draw(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_TRIANGLES);
glColor3f(0,0,1);
/* glTexCoord2f(1, 0); */
glVertex3f( 0.9, -0.9, -30.0);
glColor3f(1,0,0);
/* glTexCoord2f(1, 1); */
glVertex3f( 0.9, 0.9, -30.0);
glColor3f(0,1,0);
/* glTexCoord2f(0, .5); */
glVertex3f(-0.9, 0.0, -30.0);
glEnd();
glFlush();
}
int main(int argc, char **argv)
{
GLenum type;
glutInit(&argc, argv);
glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
type = GLUT_RGB;
type |= GLUT_SINGLE;
glutInitDisplayMode(type);
if (glutCreateWindow("First Tri") == GL_FALSE) {
exit(1);
}
Init();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
glutMainLoop();
return 0;
}
|
