ANDROID: Provide an alternate partial texture update for stride != width

The new one copies into a temp buffer and only does one
glTexSubImage2D.  I'm led to believe that this is faster on some
devices (but slower on others).  Disabled for now, but someone might
want to try both versions on their slow device.

Also manually set glColor before calling DrawTexiOES, following
mention of a bug in a discussion I stumbled across.  DrawTexiOES-use
is disabled for now, so this is a noop.

svn-id: r53803

1 files changed, 30 insertions, 10 deletions

diff --git a/backends/platform/android/video.cpp b/backends/platform/android/video.cpp
index d4c002fbd0..81a8f7fbc7 100644
--- a/backends/platform/android/video.cpp
+++ b/backends/platform/android/video.cpp
@@ -38,6 +38,9 @@
 
 #include "backends/platform/android/video.h"
 
+// Unfortunately, Android devices are too varied to make broad assumptions :/
+#define TEXSUBIMAGE_IS_EXPENSIVE 0
+
 #undef LOG_TAG
 #define LOG_TAG "ScummVM-video"
 
@@ -158,13 +161,11 @@ void GLESTexture::allocBuffer(GLuint w, GLuint h) {
 	// later (perhaps with multiple TexSubImage2D operations).
 	CHECK_GL_ERROR();
 	glBindTexture(GL_TEXTURE_2D, _texture_name);
+	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 	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(),
@@ -177,6 +178,7 @@ void GLESTexture::updateBuffer(GLuint x, GLuint y, GLuint w, GLuint h,
 							   const void* buf, int pitch) {
 	ENTER("updateBuffer(%u, %u, %u, %u, %p, %d)", x, y, w, h, buf, pitch);
 	glBindTexture(GL_TEXTURE_2D, _texture_name);
+	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
 	setDirtyRect(Common::Rect(x, y, x+w, y+h));
 
@@ -185,7 +187,25 @@ void GLESTexture::updateBuffer(GLuint x, GLuint y, GLuint w, GLuint h,
 						glFormat(), glType(), buf);
 	} else {
 		// GLES removed the ability to specify pitch, so we
-		// have to do this row by row.
+		// have to do this ourselves.
+		if (h == 0)
+			return;
+
+#if TEXSUBIMAGE_IS_EXPENSIVE
+		byte tmpbuf[w * h * bytesPerPixel()];
+		const byte* src = static_cast<const byte*>(buf);
+		byte* dst = tmpbuf;
+		GLuint count = h;
+		do {
+			memcpy(dst, src, w * bytesPerPixel());
+			dst += w * bytesPerPixel();
+			src += pitch;
+		} while (--count);
+		glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, w, h,
+						glFormat(), glType(), tmpbuf);
+#else
+		// This version avoids the intermediate copy at the expense of
+		// repeat glTexSubImage2D calls.  On some devices this is worse.
 		const byte* src = static_cast<const byte*>(buf);
 		do {
 			glTexSubImage2D(GL_TEXTURE_2D, 0, x, y,
@@ -193,16 +213,15 @@ void GLESTexture::updateBuffer(GLuint x, GLuint y, GLuint w, GLuint h,
 			++y;
 			src += pitch;
 		} while (--h);
+#endif
 	}
 }
 
 void GLESTexture::fillBuffer(byte x) {
-	byte tmpbuf[_surface.h * _surface.w * bytesPerPixel()];
-	memset(tmpbuf, 0, _surface.h * _surface.w * bytesPerPixel());
-	glBindTexture(GL_TEXTURE_2D, _texture_name);
-	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, _surface.w, _surface.h,
-					glFormat(), glType(), tmpbuf);
-	setDirty();
+	int rowbytes = _surface.w * bytesPerPixel();
+	byte tmpbuf[_surface.h * rowbytes];
+	memset(tmpbuf, x, _surface.h * rowbytes);
+	updateBuffer(0, 0, _surface.w, _surface.h, tmpbuf, rowbytes);
 }
 
 void GLESTexture::drawTexture(GLshort x, GLshort y, GLshort w, GLshort h) {
@@ -215,6 +234,7 @@ void GLESTexture::drawTexture(GLshort x, GLshort y, GLshort w, GLshort h) {
 		//glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 		const GLint crop[4] = {0, _surface.h, _surface.w, -_surface.h};
 		glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES, crop);
+		glColor4ub(0xff, 0xff, 0xff, 0xff);   // Android GLES bug?
 		glDrawTexiOES(x, y, 0, w, h);
 	} else
 #endif