aboutsummaryrefslogtreecommitdiff
path: root/backends/graphics/opengl/shader.cpp
blob: c251ec1ed92715a3b2fd2316b1221938f6a7eed3 (plain)
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
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "backends/graphics/opengl/shader.h"

#if !USE_FORCED_GLES

#include "common/textconsole.h"

namespace OpenGL {

const char *const g_defaultVertexShader = 
	"attribute vec4 position;\n"
	"attribute vec2 texCoordIn;\n"
	"attribute vec4 blendColorIn;\n"
	"\n"
	"uniform mat4 projection;\n"
	"\n"
	"varying vec2 texCoord;\n"
	"varying vec4 blendColor;\n"
	"\n"
	"void main(void) {\n"
	"\ttexCoord    = texCoordIn;\n"
	"\tblendColor  = blendColorIn;\n"
	"\tgl_Position = projection * position;\n"
	"}\n";

#if !USE_FORCED_GLES2
const char *const g_defaultFragmentShaderGL =
	"varying vec2 texCoord;\n"
	"varying vec4 blendColor;\n"
	"\n"
	"uniform sampler2D texture;\n"
	"\n"
	"void main(void) {\n"
	"\tgl_FragColor = blendColor * texture2D(texture, texCoord);\n"
	"}\n";
#endif

#if !USE_FORCED_GL
const char *const g_defaultFragmentShaderGLES2 =
	"varying lowp vec2 texCoord;\n"
	"varying lowp vec4 blendColor;\n"
	"\n"
	"uniform sampler2D texture;\n"
	"\n"
	"void main(void) {\n"
	"\tgl_FragColor = blendColor * texture2D(texture, texCoord);\n"
	"}\n";
#endif

Shader::Shader(const Common::String &vertex, const Common::String &fragment)
    : _vertex(vertex), _fragment(fragment), _program(0), _projectionLocation(-1), _textureLocation(-1) {
}

Shader::~Shader() {
	// According to extension specification glDeleteObjectARB silently ignores
	// 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
	// we do not call it with 0 as parameter to avoid warnings.
	if (_program) {
		GL_CALL_SAFE(glDeleteProgram, (_program));
	}
}

void Shader::destroy() {
	// According to extension specification glDeleteObjectARB silently ignores
	// 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
	// we do not call it with 0 as parameter to avoid warnings.
	if (_program) {
		GL_CALL(glDeleteProgram(_program));
		_program = 0;
	}
}

bool Shader::recreate() {
	// Make sure any old programs are destroyed properly.
	destroy();

	GLshader vertexShader = compileShader(_vertex.c_str(), GL_VERTEX_SHADER);
	if (!vertexShader) {
		return false;
	}

	GLshader fragmentShader = compileShader(_fragment.c_str(), GL_FRAGMENT_SHADER);
	if (!fragmentShader) {
		GL_CALL(glDeleteShader(vertexShader));
		return false;
	}

	GL_ASSIGN(_program, glCreateProgram());
	if (!_program) {
		GL_CALL(glDeleteShader(vertexShader));
		GL_CALL(glDeleteShader(fragmentShader));
		return false;
	}

	GL_CALL(glAttachShader(_program, vertexShader));
	GL_CALL(glAttachShader(_program, fragmentShader));

	GL_CALL(glBindAttribLocation(_program, kPositionAttribLocation, "position"));
	GL_CALL(glBindAttribLocation(_program, kTexCoordAttribLocation, "texCoordIn"));
	GL_CALL(glBindAttribLocation(_program, kColorAttribLocation,    "blendColorIn"));

	GL_CALL(glLinkProgram(_program));

	GL_CALL(glDetachShader(_program, fragmentShader));
	GL_CALL(glDeleteShader(fragmentShader));

	GL_CALL(glDetachShader(_program, vertexShader));
	GL_CALL(glDeleteShader(vertexShader));

	GLint result;
	GL_CALL(glGetProgramiv(_program, GL_LINK_STATUS, &result));
	if (result == GL_FALSE) {
		GLint logSize;
		GL_CALL(glGetProgramiv(_program, GL_INFO_LOG_LENGTH, &logSize));

		GLchar *log = new GLchar[logSize];
		GL_CALL(glGetProgramInfoLog(_program, logSize, nullptr, log));
		warning("Could not link shader: \"%s\"", log);
		delete[] log;

		destroy();
		return false;
	}

	GL_ASSIGN(_projectionLocation, glGetUniformLocation(_program, "projection"));
	if (_projectionLocation == -1) {
		warning("Shader misses \"projection\" uniform.");
		destroy();
		return false;
	}

	GL_ASSIGN(_textureLocation, glGetUniformLocation(_program, "texture"));
	if (_textureLocation == -1) {
		warning("Shader misses \"texture\" uniform.");
		destroy();
		return false;
	}

	return true;
}

void Shader::activate(const GLfloat *projectionMatrix) {
	// Activate program.
	GL_CALL(glUseProgram(_program));

	// Set projection matrix.
	GL_CALL(glUniformMatrix4fv(_projectionLocation, 1, GL_FALSE, projectionMatrix));

	// We always use texture unit 0.
	GL_CALL(glUniform1i(_textureLocation, 0));
}

GLint Shader::getUniformLocation(const char *name) const {
	GLint result = -1;
	GL_ASSIGN(result, glGetUniformLocation(_program, name));
	return result;
}

void Shader::setUniformI(GLint location, GLint value) {
	GL_CALL(glUniform1i(location, value));
}

GLshader Shader::compileShader(const char *source, GLenum shaderType) {
	GLshader handle;
	GL_ASSIGN(handle, glCreateShader(shaderType));
	if (!handle) {
		return 0;
	}

	GL_CALL(glShaderSource(handle, 1, &source, nullptr));
	GL_CALL(glCompileShader(handle));

	GLint result;
	GL_CALL(glGetShaderiv(handle, GL_COMPILE_STATUS, &result));
	if (result == GL_FALSE) {
		GLint logSize;
		GL_CALL(glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &logSize));

		GLchar *log = new GLchar[logSize];
		GL_CALL(glGetShaderInfoLog(handle, logSize, nullptr, log));
		warning("Could not compile shader \"%s\": \"%s\"", source, log);
		delete[] log;

		GL_CALL(glDeleteShader(handle));
		return 0;
	}

	return handle;
}

} // End of namespace OpenGL

#endif // !USE_FORCED_GLES