c3gl_fbo: New bits

Implement the framebuffer objects. It doesn't cover all the cases
but it'll help for now.

Signed-off-by: Michel Pollet <buserror@gmail.com>

diff --git a/examples/shared/libc3/srcgl/c3gl_fbo.c b/examples/shared/libc3/srcgl/c3gl_fbo.c
new file mode 100644 (file)
index 0000000..11bc385
--- /dev/null
+++ b/examples/shared/libc3/srcgl/c3gl_fbo.c
@@ -0,0 +1,160 @@
+/*
+       c3gl_fbo.c
+
+       Copyright 2008-2012 Michel Pollet <buserror@gmail.com>
+
+       This file is part of libc3.
+
+       simavr 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.
+
+       simavr 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 simavr.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#if __APPLE__
+#define GL_GLEXT_PROTOTYPES
+#include <GLUT/glut.h>
+#include <OpenGL/gl.h>
+#include <OpenGL/glext.h>
+#else
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <GL/glext.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+
+#include "c3gl_fbo.h"
+
+
+#define GLCHECK(_w) {_w; dumpError(#_w);}
+static int dumpError(const char * what)
+{
+       GLenum e;
+       int count = 0;
+       while ((e = glGetError()) != GL_NO_ERROR) {
+               printf("%s: %s\n", what, gluErrorString(e));
+               count++;
+       }
+       return count;
+}
+
+int
+c3gl_fbo_create(
+               c3gl_fbo_p b,
+               c3vec2 size,
+               uint32_t flags )
+{
+       memset(b, 0, sizeof(*b));
+       b->size = size;
+       b->flags = flags;
+
+       /* Texture */
+       GLCHECK(glActiveTexture(GL_TEXTURE0));
+
+       if (b->flags & (1 << C3GL_FBO_COLOR)) {
+               GLuint tex;
+               glGenTextures(1, &tex);
+               glBindTexture(GL_TEXTURE_2D, tex);
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+               glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
+                               b->size.x, b->size.y, 0,
+                               GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+               glBindTexture(GL_TEXTURE_2D, 0);
+               b->buffers[C3GL_FBO_COLOR].bid = (c3apiobject_t)tex;
+       }
+
+       /* Depth buffer */
+       if (b->flags & (1 << C3GL_FBO_DEPTH)) {
+               GLuint rbo_depth;
+               GLCHECK(glGenRenderbuffers(1, &rbo_depth));
+               glBindRenderbuffer(GL_RENDERBUFFER, rbo_depth);
+               glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
+                               b->size.x, b->size.y);
+               glBindRenderbuffer(GL_RENDERBUFFER, 0);
+               b->buffers[C3GL_FBO_DEPTH].bid = (c3apiobject_t)rbo_depth;
+       }
+
+       /* Framebuffer to link everything together */
+       GLuint fbo;
+       GLCHECK(glGenFramebuffers(1, &fbo));
+       glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+       if (b->flags & (1 << C3GL_FBO_COLOR)) {
+               glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                               GL_TEXTURE_2D, (GLuint)b->buffers[C3GL_FBO_COLOR].bid, 0);
+               // Set the list of draw buffers.
+               GLenum DrawBuffers[2] = { GL_COLOR_ATTACHMENT0 };
+               glDrawBuffers(1, DrawBuffers); // "1" is the size of DrawBuffers
+       } else
+               glDrawBuffers(0, NULL); // "1" is the size of DrawBuffers
+
+       if (b->flags & (1 << C3GL_FBO_DEPTH))
+               glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+               GL_RENDERBUFFER, (GLuint)b->buffers[C3GL_FBO_DEPTH].bid);
+       b->fbo = (c3apiobject_t)fbo;
+
+       GLenum status;
+       if ((status = glCheckFramebufferStatus(GL_FRAMEBUFFER))
+               != GL_FRAMEBUFFER_COMPLETE) {
+               fprintf(stderr, "%s: glCheckFramebufferStatus: error %d", __func__, (int)status);
+               return -1 ;
+       }
+
+       glBindFramebuffer(GL_FRAMEBUFFER, 0);
+       return 0;
+}
+
+void
+c3gl_fbo_resize(
+               c3gl_fbo_p b,
+               c3vec2 size)
+{
+       b->size = size;
+// Rescale FBO and RBO as well
+       if (b->flags & (1 << C3GL_FBO_COLOR)) {
+               glBindTexture(GL_TEXTURE_2D, (GLuint)b->buffers[C3GL_FBO_COLOR].bid);
+               glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
+                               b->size.x, b->size.y, 0,
+                               GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+               glBindTexture(GL_TEXTURE_2D, 0);
+       }
+
+       if (b->flags & (1 << C3GL_FBO_DEPTH)) {
+               glBindRenderbuffer(GL_RENDERBUFFER, (GLuint)b->buffers[C3GL_FBO_DEPTH].bid);
+               glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
+                               b->size.x, b->size.y);
+               glBindRenderbuffer(GL_RENDERBUFFER, 0);
+       }
+}
+
+void
+c3gl_fbo_dispose(
+               c3gl_fbo_p b )
+{
+       /* free_resources */
+       if (b->flags & (1 << C3GL_FBO_DEPTH)) {
+               GLuint bid = (GLuint)b->buffers[C3GL_FBO_DEPTH].bid;
+               glDeleteRenderbuffers(1, &bid);
+       }
+       if (b->flags & (1 << C3GL_FBO_COLOR)) {
+               GLuint bid = (GLuint)b->buffers[C3GL_FBO_COLOR].bid;
+               glDeleteTextures(1, &bid);
+       }
+       GLuint fbo = (GLuint)b->fbo;
+       glDeleteFramebuffers(1, &fbo);
+       memset(b, 0, sizeof(*b));
+}
+

diff --git a/examples/shared/libc3/srcgl/c3gl_fbo.h b/examples/shared/libc3/srcgl/c3gl_fbo.h
new file mode 100644 (file)
index 0000000..2ada1cf
--- /dev/null
+++ b/examples/shared/libc3/srcgl/c3gl_fbo.h
@@ -0,0 +1,58 @@
+/*
+       c3gl_fbo.h
+
+       Copyright 2008-2012 Michel Pollet <buserror@gmail.com>
+
+       This file is part of libc3.
+
+       simavr 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.
+
+       simavr 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 simavr.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef __C3GL_FBO_H___
+#define __C3GL_FBO_H___
+
+#include "c3types.h"
+
+enum {
+       C3GL_FBO_COLOR  = 0,
+       C3GL_FBO_DEPTH,
+       C3GL_FBO_MAX,
+};
+
+typedef struct c3gl_fbo_t {
+       c3vec2                  size;
+       uint32_t                flags;
+       c3apiobject_t   fbo;
+       struct {
+               c3apiobject_t   bid;
+               // ... ?
+       } buffers[8];
+} c3gl_fbo_t, *c3gl_fbo_p;
+
+
+int
+c3gl_fbo_create(
+               c3gl_fbo_p b,
+               c3vec2 size,
+               uint32_t flags );
+void
+c3gl_fbo_resize(
+               c3gl_fbo_p b,
+               c3vec2 size);
+void
+c3gl_fbo_dispose(
+               c3gl_fbo_p b );
+
+#endif /* __C3GL_FBO_H___ */