Initial commit

engines/freescape/gfx_opengl_texture.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 "common/scummsys.h"
+
+#if defined(USE_OPENGL_GAME) || defined(USE_OPENGL_SHADERS)
+
+#include "freescape/gfx_opengl_texture.h"
+
+#include "graphics/opengl/context.h"
+
+namespace Freescape {
+
+// From Bit Twiddling Hacks
+static uint32 upperPowerOfTwo(uint32 v) {
+	v--;
+	v |= v >> 1;
+	v |= v >> 2;
+	v |= v >> 4;
+	v |= v >> 8;
+	v |= v >> 16;
+	v++;
+	return v;
+}
+
+OpenGLTexture::OpenGLTexture() :
+	_internalFormat(0),
+	_sourceFormat(0),
+	_internalWidth(0),
+	_internalHeight(0),
+	_upsideDown(false) {
+	glGenTextures(1, &_id);
+}
+
+OpenGLTexture::OpenGLTexture(const Graphics::Surface *surface) {
+	_width = surface->w;
+	_height = surface->h;
+	_format = surface->format;
+	_upsideDown = false;
+
+	// Pad the textures if non power of two support is unavailable
+	if (OpenGLContext.NPOTSupported) {
+		_internalHeight = _height;
+		_internalWidth = _width;
+	} else {
+		_internalHeight = upperPowerOfTwo(_height);
+		_internalWidth = upperPowerOfTwo(_width);
+	}
+
+	if (_format.bytesPerPixel == 4) {
+		assert(surface->format == getRGBAPixelFormat());
+		_format = surface->format;
+		_internalFormat = GL_RGBA;
+		_sourceFormat = GL_UNSIGNED_BYTE;
+	} else if (_format.bytesPerPixel == 2) {
+		_internalFormat = GL_RGB;
+		_sourceFormat = GL_UNSIGNED_SHORT_5_6_5;
+	} else
+		error("Unknown pixel format");
+
+	glGenTextures(1, &_id);
+	glBindTexture(GL_TEXTURE_2D, _id);
+	glTexImage2D(GL_TEXTURE_2D, 0, _internalFormat, _internalWidth, _internalHeight, 0, _internalFormat, _sourceFormat, nullptr);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	// TODO: If non power of two textures are unavailable this clamping
+	// has no effect on the padded sides (resulting in white lines on the edges)
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+	update(surface);
+}
+
+OpenGLTexture::~OpenGLTexture() {
+	glDeleteTextures(1, &_id);
+}
+
+void OpenGLTexture::update(const Graphics::Surface *surface) {
+	updatePartial(surface, Common::Rect(surface->w, surface->h));
+}
+
+void OpenGLTexture::updateTexture(const Graphics::Surface *surface, const Common::Rect &rect) {
+	assert(surface->format == _format);
+
+	glBindTexture(GL_TEXTURE_2D, _id);
+	glTexImage2D(GL_TEXTURE_2D, 0, _internalFormat, surface->w, surface->h, 0, _internalFormat, _sourceFormat, const_cast<void *>(surface->getPixels()));
+}
+
+void OpenGLTexture::updatePartial(const Graphics::Surface *surface, const Common::Rect &rect) {
+	updateTexture(surface, rect);
+}
+
+} // End of namespace Freescape
+
+#endif