graphics

commit d391a6083cbaaae1caf07e7af514a501093f473a
parent b695b9d6b2b2da872f6cd0c1ec1ef36f0ac5b314
Author: Brian Swetland <swetland@frotz.net>
Date:   Sun, 15 Sep 2013 05:20:47 -0700

core: add FrameBuffer object for render-to-texture

Diffstat:
M
common/buffers.cc
 | 
36
++++++++++++++++++++++++++++++++++++
M
common/core.h
 | 
19
+++++++++++++++++++
M
common/module.mk
 | 
1
+

3 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/common/buffers.cc b/common/buffers.cc
@@ -149,3 +149,39 @@ int Texture2D::createRGBA(unsigned w, unsigned h) {
 	height = h;
 	return 0;
 }
+
+void FrameBuffer::init(unsigned w, unsigned h, unsigned _depth) {
+	glGenTextures(1, &txid);
+	glActiveTexture(GL_TEXTURE0 + 15);
+	glBindTexture(GL_TEXTURE_RECTANGLE, txid);
+	glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_BASE_LEVEL, 0);
+	glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAX_LEVEL, 0);
+	glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	if (_depth) {
+		glGenRenderbuffers(1, &depth);
+		glBindRenderbuffer(GL_RENDERBUFFER, depth);
+		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, w, h);
+		glBindRenderbuffer(GL_RENDERBUFFER, 0);
+	}
+
+	glGenFramebuffers(1, &id);
+	glBindFramebuffer(GL_FRAMEBUFFER, id);
+
+	/* color buffer */
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+		GL_TEXTURE_RECTANGLE, txid, 0);
+
+	/* depth buffer */
+	if (_depth) {
+		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+			GL_RENDERBUFFER, depth);
+	}
+
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	width = w;
+	height = h;
+}
diff --git a/common/core.h b/common/core.h
@@ -141,5 +141,24 @@ struct VertexAttributes {
 	void use(void) { glBindVertexArray(vao); };
 };
 
+class FrameBuffer {
+public:
+	FrameBuffer() : id(0), txid(0), depth(0) {}
+	void init(unsigned w, unsigned h, unsigned _depth = 1);
+	void useTexture(unsigned index) {
+		glActiveTexture(GL_TEXTURE0 + index);
+		glBindTexture(GL_TEXTURE_RECTANGLE, txid);
+	}
+	void use(void) {
+		glBindFramebuffer(GL_FRAMEBUFFER, id);
+		glViewport(0, 0, width, height);
+	}
+private:
+	u32 id;
+	u32 txid;
+	u32 depth;
+	u32 width;
+	u32 height;
+};
 #endif
 
diff --git a/common/module.mk b/common/module.mk
@@ -13,6 +13,7 @@ M_OBJS += savepng.o
 M_OBJS += simplexnoise.o
 M_OBJS += textgrid.o
 M_OBJS += texturefont.o
+M_OBJS += Renderable.o
 M_OBJS += Model.o
 M_OBJS += Effect.o
 M_LIBS := common