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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/*
* Copyright (c) 2011 VMware, Inc.
*
* 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 (including the next
* paragraph) 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
* THE AUTHORS OR COPYRIGHT HOLDERS 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.
*/
/**
* @file fbo-fragcoord2.c
*
* Test GLSL gl_FragCoord, gl_Frontfacing, polygon CCW vs CW and culling
* with an FBO
*
* Author: Brian Paul
*/
#include "piglit-util.h"
#include "piglit-framework.h"
PIGLIT_GL_TEST_MAIN(
256 /*window_width*/,
256 /*window_height*/,
GLUT_RGB | GLUT_DOUBLE)
static GLuint prog;
static const char *TestName = "fbo-fragcoord2";
static GLuint FBO;
static char *VertShaderText =
"void main() \n"
"{ \n"
" gl_Position = ftransform(); \n"
"} \n";
static char *FragShaderText =
"void main() \n"
"{ \n"
" vec4 scale = vec4(1.0/255.0, 1.0/255.0, 1.0, 1.0); \n"
" if (gl_FrontFacing) { \n"
" // front-facing \n"
" gl_FragColor = gl_FragCoord * scale; \n"
" gl_FragColor.z = 0.0; \n"
" } else { \n"
" // back-facing \n"
" gl_FragColor = vec4(0, 0, 1, 1); \n"
" } \n"
"} \n";
static void
check_error(int line)
{
GLenum err = glGetError();
if (err) {
printf("%s: Unexpected error 0x%x at line %d\n",
TestName, err, line);
piglit_report_result(PIGLIT_FAIL);
}
}
static void
create_fbo(void)
{
GLuint rb;
glGenFramebuffersEXT(1, &FBO);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, FBO);
glGenRenderbuffersEXT(1, &rb);
check_error(__LINE__);
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
check_error(__LINE__);
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER_EXT,
rb);
check_error(__LINE__);
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA,
piglit_width, piglit_height);
check_error(__LINE__);
}
static void
rect(float x0, float y0, float x1, float y1)
{
glBegin(GL_POLYGON);
glVertex2f(x0, y0);
glVertex2f(x1, y0);
glVertex2f(x1, y1);
glVertex2f(x0, y1);
glEnd();
}
static enum piglit_result
test(void)
{
static const GLfloat black[4] = {0, 0, 0, 1};
static const GLfloat blue[4] = {0, 0, 1, 1};
static const GLfloat half_red[4] = {0.5, 0, 0, 1};
static const GLfloat half_green[4] = {0, 0.5, 0, 1};
static const GLfloat green_half_red[4] = {0.5, 1, 0, 1};
GLenum buffer;
enum piglit_result result = PIGLIT_PASS;
create_fbo();
/* draw to fbo */
buffer = GL_COLOR_ATTACHMENT0_EXT;
glDrawBuffersARB(1, &buffer);
glReadBuffer(buffer);
/* test drawing */
glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(prog);
glEnable(GL_CULL_FACE);
/* left half: front-facing, color varies with fragcoord */
glFrontFace(GL_CCW);
glCullFace(GL_BACK);
rect(0, 0, piglit_width / 2, piglit_height);
/* right half: back-facing, blue */
glFrontFace(GL_CW);
glCullFace(GL_FRONT);
rect(piglit_width/2, 0, piglit_width, piglit_height);
glUseProgram(0);
glDisable(GL_CULL_FACE);
/* copy image from FBO to window */
{
GLubyte *buf;
buf = malloc(piglit_width * piglit_height * 4);
glReadPixels(0, 0, piglit_width, piglit_height, GL_RGBA, GL_UNSIGNED_BYTE, buf);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
glDrawBuffer(GL_BACK);
glClear(GL_COLOR_BUFFER_BIT);
glDrawPixels(piglit_width, piglit_height, GL_RGBA, GL_UNSIGNED_BYTE, buf);
free(buf);
}
/* left half probes */
if (!piglit_probe_pixel_rgb(0, 0, black)) {
result = PIGLIT_FAIL;
}
if (!piglit_probe_pixel_rgb(piglit_width/2-1, 0, half_red)) {
result = PIGLIT_FAIL;
}
if (!piglit_probe_pixel_rgb(0, piglit_height/2, half_green)) {
result = PIGLIT_FAIL;
}
if (!piglit_probe_pixel_rgb(piglit_width/2-1, piglit_height-1, green_half_red)) {
result = PIGLIT_FAIL;
}
/* right half probe */
if (!piglit_probe_pixel_rgb(piglit_width*3/4, piglit_height/2, blue)) {
result = PIGLIT_FAIL;
}
glutSwapBuffers();
return result;
}
enum piglit_result
piglit_display(void)
{
return test();
}
void
piglit_init(int argc, char**argv)
{
GLuint vs, fs;
if (piglit_get_gl_version() < 20) {
printf("Requires OpenGL 2.0\n");
piglit_report_result(PIGLIT_SKIP);
}
piglit_require_extension("GL_ARB_framebuffer_object");
piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
vs = piglit_compile_shader_text(GL_VERTEX_SHADER, VertShaderText);
assert(vs);
fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, FragShaderText);
assert(fs);
prog = piglit_link_simple_program(vs, fs);
assert(prog);
}
|
