Initial commit

backends/graphics/opengl/pipelines/shader.cpp

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "backends/graphics/opengl/pipelines/shader.h"
+#include "backends/graphics/opengl/shader.h"
+#include "backends/graphics/opengl/framebuffer.h"
+#include "graphics/opengl/debug.h"
+
+namespace OpenGL {
+
+// A 4 elements with 2 components vector of floats
+static const int kCoordinatesSize = 4 * 2 * sizeof(float);
+
+#if !USE_FORCED_GLES
+ShaderPipeline::ShaderPipeline(Shader *shader)
+	: _activeShader(shader), _colorAttributes(), _colorDirty(true) {
+	// Use the same VBO for vertices and texcoords as we modify them at the same time
+	_coordsVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, kCoordinatesSize, nullptr, GL_STATIC_DRAW);
+	_activeShader->enableVertexAttribute("position", _coordsVBO, 2, GL_FLOAT, GL_FALSE, 0, 0);
+	_texcoordsVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, kCoordinatesSize, nullptr, GL_STATIC_DRAW);
+	_activeShader->enableVertexAttribute("texCoordIn", _texcoordsVBO, 2, GL_FLOAT, GL_FALSE, 0, 0);
+	_colorVBO = OpenGL::Shader::createBuffer(GL_ARRAY_BUFFER, sizeof(_colorAttributes), nullptr, GL_DYNAMIC_DRAW);
+	_activeShader->enableVertexAttribute("blendColorIn", _colorVBO, 4, GL_FLOAT, GL_FALSE, 0, 0);
+}
+
+ShaderPipeline::~ShaderPipeline() {
+	delete _activeShader;
+
+	OpenGL::Shader::freeBuffer(_coordsVBO);
+	OpenGL::Shader::freeBuffer(_texcoordsVBO);
+	OpenGL::Shader::freeBuffer(_colorVBO);
+}
+
+void ShaderPipeline::activateInternal() {
+	Pipeline::activateInternal();
+
+	// Disable 3D properties.
+	GL_CALL(glDisable(GL_CULL_FACE));
+	GL_CALL(glDisable(GL_DEPTH_TEST));
+	GL_CALL(glDisable(GL_DITHER));
+
+	if (OpenGLContext.multitextureSupported) {
+		GL_CALL(glActiveTexture(GL_TEXTURE0));
+	}
+
+	_activeShader->use();
+}
+
+void ShaderPipeline::deactivateInternal() {
+	_activeShader->unbind();
+
+	Pipeline::deactivateInternal();
+}
+
+void ShaderPipeline::setColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a) {
+	GLfloat *dst = _colorAttributes;
+	for (uint i = 0; i < 4; ++i) {
+		*dst++ = r;
+		*dst++ = g;
+		*dst++ = b;
+		*dst++ = a;
+	}
+	_colorDirty = true;
+}
+
+void ShaderPipeline::drawTextureInternal(const Texture &texture, const GLfloat *coordinates, const GLfloat *texcoords) {
+	assert(isActive());
+
+	texture.bind();
+
+	if (_colorDirty) {
+		GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _colorVBO));
+		GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(_colorAttributes), _colorAttributes));
+		_colorDirty = false;
+	}
+	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _coordsVBO));
+	GL_CALL(glBufferData(GL_ARRAY_BUFFER, kCoordinatesSize, coordinates, GL_STATIC_DRAW));
+	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, _texcoordsVBO));
+	GL_CALL(glBufferData(GL_ARRAY_BUFFER, kCoordinatesSize, texcoords, GL_STATIC_DRAW));
+	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, 0));
+
+	GL_CALL(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
+}
+
+void ShaderPipeline::setProjectionMatrix(const Math::Matrix4 &projectionMatrix) {
+	assert(isActive());
+
+	_activeShader->setUniform("projection", projectionMatrix);
+}
+#endif // !USE_FORCED_GLES
+
+} // End of namespace OpenGL