Added BaseSdlGraphicsManager. Added GLTexture.

svn-id: r50795

1 files changed, 173 insertions, 0 deletions

diff --git a/backends/graphics/opengl/gltexture.cpp b/backends/graphics/opengl/gltexture.cpp
new file mode 100644
index 0000000000..de9bd13eaf
--- /dev/null
+++ b/backends/graphics/opengl/gltexture.cpp
@@ -0,0 +1,173 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#include "backends/graphics/opengl/gltexture.h"
+#include "backends/graphics/opengl/glerrorcheck.h"
+
+#include "common/rect.h"
+#include "common/array.h"
+#include "common/util.h"
+#include "common/tokenizer.h"
+
+// Supported GL extensions
+static bool npot_supported = false;
+
+static inline GLint xdiv(int numerator, int denominator) {
+	assert(numerator < (1 << 16));
+	return (numerator << 16) / denominator;
+}
+
+template <class T>
+static T nextHigher2(T k) {
+	if (k == 0)
+		return 1;
+	--k;
+	for (uint i = 1; i < sizeof(T) * CHAR_BIT; i <<= 1)
+		k = k | k >> i;
+	return k + 1;
+}
+
+void GLTexture::initGLExtensions() {
+	const char* ext_string =
+		reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
+	Common::StringTokenizer tokenizer(ext_string, " ");
+	while (!tokenizer.empty()) {
+		Common::String token = tokenizer.nextToken();
+		if (token == "GL_ARB_texture_non_power_of_two")
+			npot_supported = true;
+	}
+}
+
+GLTexture::GLTexture() :
+	_textureWidth(0),
+	_textureHeight(0) {
+
+	refresh();
+
+	// This all gets reset later in allocBuffer:
+	_surface.w = 0;
+	_surface.h = 0;
+	_surface.pitch = 0;
+	_surface.pixels = NULL;
+	_surface.bytesPerPixel = 0;
+}
+
+GLTexture::~GLTexture() {
+	debug("Destroying texture %u", _textureName);
+	CHECK_GL_ERROR( glDeleteTextures(1, &_textureName) );
+}
+
+void GLTexture::refresh() {
+	// Generates the texture ID for GL
+	CHECK_GL_ERROR( glGenTextures(1, &_textureName) );
+}
+
+void GLTexture::allocBuffer(GLuint w, GLuint h) {
+	int bpp = bytesPerPixel();
+	_surface.w = w;
+	_surface.h = h;
+	_surface.bytesPerPixel = bpp;
+
+	if (w <= _textureWidth && h <= _textureHeight)
+		// Already allocated a sufficiently large buffer
+		return;
+
+	if (npot_supported) {
+		_textureWidth = _surface.w;
+		_textureHeight = _surface.h;
+	} else {
+		_textureWidth = nextHigher2(_surface.w);
+		_textureHeight = nextHigher2(_surface.h);
+	}
+	_surface.pitch = _textureWidth * bpp;
+
+	_surface.create(w, h, bytesPerPixel());
+
+	// Allocate room for the texture now, but pixel data gets uploaded
+	// later (perhaps with multiple TexSubImage2D operations).
+	CHECK_GL_ERROR( glBindTexture(GL_TEXTURE_2D, _textureName) );
+	CHECK_GL_ERROR( glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST) );
+	CHECK_GL_ERROR( glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST) );
+	CHECK_GL_ERROR( glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE) );
+	CHECK_GL_ERROR( glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE) );
+	CHECK_GL_ERROR( glTexImage2D(GL_TEXTURE_2D, 0, glFormat(),
+		     _textureWidth, _textureHeight,
+		     0, glFormat(), glType(), NULL) );
+}
+
+void GLTexture::updateBuffer(GLuint x, GLuint y, GLuint w, GLuint h, const void* buf, int pitch) {
+	CHECK_GL_ERROR( glBindTexture(GL_TEXTURE_2D, _textureName) );
+
+	if (static_cast<int>(w) * bytesPerPixel() == pitch) {
+		CHECK_GL_ERROR( glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, w, h,
+						glFormat(), glType(), buf) );
+		memcpy(_surface.pixels, buf, w * pitch);
+	} else {
+		// GLES removed the ability to specify pitch, so we
+		// have to do this row by row.
+		const byte* src = static_cast<const byte*>(buf);
+		do {
+			CHECK_GL_ERROR( glTexSubImage2D(GL_TEXTURE_2D, 0, x, y,
+							w, 1, glFormat(), glType(), src) );
+			memcpy(_surface.pixels, src, pitch);
+			++y;
+			src += pitch;
+		} while (--h);
+	}
+}
+
+void GLTexture::fillBuffer(byte x) {
+	byte* tmpbuf = new byte[_surface.h * _surface.w * bytesPerPixel()];
+	memset(tmpbuf, 0, _surface.h * _surface.w * bytesPerPixel());
+	CHECK_GL_ERROR( glBindTexture(GL_TEXTURE_2D, _textureName) );
+	CHECK_GL_ERROR( glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, _surface.w, _surface.h,
+					glFormat(), glType(), tmpbuf) );
+	delete[] tmpbuf;
+}
+
+void GLTexture::drawTexture(GLshort x, GLshort y, GLshort w, GLshort h) {
+	CHECK_GL_ERROR( glBindTexture(GL_TEXTURE_2D, _textureName) );
+
+	const GLint tex_width = xdiv(_surface.w, _textureWidth);
+	const GLint tex_height = xdiv(_surface.h, _textureHeight);
+	const GLint texcoords[] = {
+		0, 0,
+		tex_width, 0,
+		0, tex_height,
+		tex_width, tex_height,
+	};
+	CHECK_GL_ERROR( glTexCoordPointer(2, GL_INT, 0, texcoords) );
+
+	const GLshort vertices[] = {
+		x,	   y,
+		x + w, y,
+		x,	   y + h,
+		x + w, y + h,
+	};
+	CHECK_GL_ERROR( glVertexPointer(2, GL_SHORT, 0, vertices) );
+
+	assert(ARRAYSIZE(vertices) == ARRAYSIZE(texcoords));
+	CHECK_GL_ERROR( glDrawArrays(GL_TRIANGLE_STRIP, 0, ARRAYSIZE(vertices) / 2) );
+}