From 91f4e2681bd076de71fda1cb91f9412af9927ceb Mon Sep 17 00:00:00 2001
From: Joel Teichroeb <joel@teichroeb.net>
Date: Fri, 17 Jan 2014 09:48:06 -0800
Subject: [PATCH] GRIM: Add a vertex buffer object for blast text drawing

This makes it so that we don't have to destroy the VBO
that a blast text object uses. This fixes what is probably
a driver bug with the windows nvidia drivers.
---
 engines/grim/gfx_opengl_shaders.cpp | 16 +++++++++++++---
 engines/grim/gfx_opengl_shaders.h   |  1 +
 engines/grim/textobject.h           |  1 +
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/engines/grim/gfx_opengl_shaders.cpp b/engines/grim/gfx_opengl_shaders.cpp
index e905f75046f..19064c3304e 100644
--- a/engines/grim/gfx_opengl_shaders.cpp
+++ b/engines/grim/gfx_opengl_shaders.cpp
@@ -291,6 +291,8 @@ void GfxOpenGLS::setupShaders() {
 	setupTexturedQuad();
 	setupTexturedCenteredQuad();
 	setupPrimitives();
+
+	_blastVBO = Graphics::Shader::createBuffer(GL_ARRAY_BUFFER, 128 * 16 * sizeof(float), NULL, GL_DYNAMIC_DRAW);
 }
 
 byte *GfxOpenGLS::setupScreen(int screenW, int screenH, bool fullscreen) {
@@ -1069,8 +1071,14 @@ void GfxOpenGLS::createTextObject(TextObject *text) {
 			x += font->getCharWidth(character);
 		}
 	}
-
-	GLuint vbo = Graphics::Shader::createBuffer(GL_ARRAY_BUFFER, numCharacters * 16 * sizeof(float), bufData, GL_STATIC_DRAW);
+	GLuint vbo;
+	if (text->isBlastDraw()) {
+		vbo = _blastVBO;
+		glBindBuffer(GL_ARRAY_BUFFER, vbo);
+		glBufferSubData(GL_ARRAY_BUFFER, 0, numCharacters * 16 * sizeof(float), bufData);
+	} else {
+		vbo = Graphics::Shader::createBuffer(GL_ARRAY_BUFFER, numCharacters * 16 * sizeof(float), bufData, GL_STATIC_DRAW);
+	}
 
 	Graphics::Shader * textShader = _textProgram->clone();
 	glBindBuffer(GL_ARRAY_BUFFER, vbo);
@@ -1107,7 +1115,9 @@ void GfxOpenGLS::drawTextObject(const TextObject *text) {
 
 void GfxOpenGLS::destroyTextObject(TextObject *text) {
 	const TextUserData * td = (const TextUserData *) text->getUserData();
-	glDeleteBuffers(1, &td->shader->getAttributeAt(0)._vbo);
+	if (!text->isBlastDraw()) {
+		glDeleteBuffers(1, &td->shader->getAttributeAt(0)._vbo);
+	}
 	text->setUserData(NULL);
 	delete td;
 }
diff --git a/engines/grim/gfx_opengl_shaders.h b/engines/grim/gfx_opengl_shaders.h
index 3123c0f2f1b..977ef89a4dc 100644
--- a/engines/grim/gfx_opengl_shaders.h
+++ b/engines/grim/gfx_opengl_shaders.h
@@ -261,6 +261,7 @@ private:
 	uint32 _currentPrimitive;
 	void drawGenericPrimitive(const float *vertices, uint32 numVertices, const PrimitiveObject *primitive);
 	GLuint _irisVBO;
+	GLuint _blastVBO;
 };
 }
 #endif
diff --git a/engines/grim/textobject.h b/engines/grim/textobject.h
index 5982bc0dd18..3a8224e7023 100644
--- a/engines/grim/textobject.h
+++ b/engines/grim/textobject.h
@@ -101,6 +101,7 @@ public:
 
 	void setIsSpeech() { _isSpeech = true; }
 	void setBlastDraw() { _blastDraw = true; }
+	bool isBlastDraw() { return _blastDraw; }
 
 	const void *getUserData() const { return _userData; }
 	void setUserData(void *data) { _userData = data; }