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
|
// Copyright 2021 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <emscripten/emscripten.h>
#include <emscripten/html5.h>
#include <GLES3/gl3.h>
#include <stdlib.h>
GLuint CompileShader(GLenum type, const char *src)
{
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &src, NULL);
glCompileShader(shader);
GLint isCompiled = 0;
glGetShaderiv(shader, GL_COMPILE_STATUS, &isCompiled);
if (!isCompiled)
{
GLint maxLength = 0;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &maxLength);
char *buf = (char*)malloc(maxLength+1);
glGetShaderInfoLog(shader, maxLength, &maxLength, buf);
printf("%s\n", buf);
free(buf);
return 0;
}
else
{
printf("Shader compiled OK!\n");
}
return shader;
}
GLuint CreateProgram(GLuint vertexShader, GLuint fragmentShader)
{
GLuint program = glCreateProgram();
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glBindAttribLocation(program, 0, "pos");
glLinkProgram(program);
GLint linked = 0;
glGetProgramiv(program, GL_LINK_STATUS, &linked);
if (!linked)
{
GLint infoLen = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &infoLen);
if (infoLen)
{
char *infoLog = (char*)malloc(infoLen);
glGetProgramInfoLog(program, infoLen, NULL, infoLog);
printf("Error linking program:\n%s\n", infoLog);
}
assert(0);
}
return program;
}
int main(int argc, char *argv[])
{
EmscriptenWebGLContextAttributes attr;
emscripten_webgl_init_context_attributes(&attr);
attr.majorVersion = 2;
EMSCRIPTEN_WEBGL_CONTEXT_HANDLE ctx = emscripten_webgl_create_context("#canvas", &attr);
emscripten_webgl_make_context_current(ctx);
GLuint vs = CompileShader(GL_VERTEX_SHADER,
"#version 300 es\n"
"in vec4 pos;\n"
"void main() { gl_Position = pos; }");
GLuint ps = CompileShader(GL_FRAGMENT_SHADER,
"#version 300 es\n"
"precision lowp float;\n"
"layout(binding = 4) uniform red { vec4 unused1; float r; };\n"
"layout(binding = 5, std140) uniform Green { float unused2; float g; } green;\n"
"layout(std140, binding = 6) uniform Blue { vec3 unused3; float b; } blue[2];\n"
"out vec4 outColor;\n"
"void main() { outColor = vec4(r, green.g, blue[0].b + blue[1].b, 1.0); }");
GLuint program = CreateProgram(vs, ps);
glUseProgram(program);
int numBlocks;
glGetProgramiv(program, GL_ACTIVE_UNIFORM_BLOCKS, &numBlocks);
for(int i = 0; i < numBlocks; ++i) {
int size = -1;
glGetActiveUniformBlockiv(program, i, GL_UNIFORM_BLOCK_DATA_SIZE, &size);
printf("Uniform block at index %d: size: %d\n", i, size);
}
static const float vb[] = {
-1.0f, -1.0f,
1.0f, -1.0f,
-1.0f, 1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f,
};
GLuint vbo;
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vb), vb, GL_STATIC_DRAW);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 8, 0);
glEnableVertexAttribArray(0);
struct {
float unused1[4];
float r;
float unused2[3];
} red = { 0, 0, 0, 0, 0.3f };
printf("sizeof(red)=%d\n", (int)sizeof(red));
struct {
float unused1;
float g;
float unused2[2];
} green = { 0, 0.5f };
printf("sizeof(green)=%d\n", (int)sizeof(green));
struct {
float unused1[3];
float b;
} blue[2] = { { 0, 0, 0, 0.3f }, { 0, 0, 0.f, 0.6f } };
printf("sizeof(blue[0])=%d\n", (int)sizeof(blue[0]));
GLuint bufs[4];
glGenBuffers(4, bufs);
glBindBuffer(GL_UNIFORM_BUFFER, bufs[0]);
glBufferData(GL_UNIFORM_BUFFER, sizeof(red), &red, GL_STATIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, bufs[1]);
glBufferData(GL_UNIFORM_BUFFER, sizeof(green), &green, GL_STATIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, bufs[2]);
glBufferData(GL_UNIFORM_BUFFER, sizeof(blue[0]), blue, GL_STATIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, bufs[3]);
glBufferData(GL_UNIFORM_BUFFER, sizeof(blue[1]), blue+1, GL_STATIC_DRAW);
glBindBufferBase(GL_UNIFORM_BUFFER, 4, bufs[0]);
glBindBufferBase(GL_UNIFORM_BUFFER, 5, bufs[1]);
glBindBufferBase(GL_UNIFORM_BUFFER, 6, bufs[2]);
glBindBufferBase(GL_UNIFORM_BUFFER, 7, bufs[3]);
glClearColor(0.1f,0.1f,0.1f,1);
glClear(GL_COLOR_BUFFER_BIT);
glDrawArrays(GL_TRIANGLES, 0, 6);
uint8_t data[4];
glReadPixels(160, 85, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, data);
printf("output color: %u, %u, %u, %u\n", data[0], data[1], data[2], data[3]);
#define DIFF(x, y) ((x)-(y) < 0 ? (y) - (x) : (x) - (y))
assert(DIFF(data[0], 76) <= 1);
assert(DIFF(data[1], 127) <= 1);
assert(DIFF(data[2], 229) <= 1);
assert(data[3] == 255);
// Try binding to a negative binding point, should fail:
assert(!glGetError());
printf("The following compile should produce an error:\n");
CompileShader(GL_FRAGMENT_SHADER,
"#version 300 es\n"
"precision lowp float;\n"
"layout(binding = -1) uniform red { float r; };\n"
"out vec4 outColor;\n"
"void main() { outColor = vec4(r, r, r, 1.0); }");
assert(glGetError());
// Try binding to a too high binding point, should fail:
GLint bindingPoints = 0;
glGetIntegerv(GL_MAX_COMBINED_UNIFORM_BLOCKS, &bindingPoints);
assert(bindingPoints > 0);
assert(!glGetError());
char str[1024];
sprintf(str,
"#version 300 es\n"
"precision lowp float;\n"
"layout(binding = %d) uniform red { float r; };\n"
"out vec4 outColor;\n"
"void main() { outColor = vec4(r, r, r, 1.0); }", bindingPoints);
printf("The following compile should produce an error:\n");
CompileShader(GL_FRAGMENT_SHADER, str);
assert(glGetError());
assert(!glGetError());
// Test that glUseProgram(0) succeeds without errors.
glUseProgram(0);
assert(!glGetError());
printf("Test passed!\n");
return 0;
}
|
