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-rw-r--r--src/mesa/main/framebuffer.c165
1 files changed, 109 insertions, 56 deletions
diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index dab449fc09a..aba887a796f 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -32,6 +32,7 @@
#include "glheader.h"
#include "imports.h"
+#include "buffers.h"
#include "context.h"
#include "depthstencil.h"
#include "mtypes.h"
@@ -108,8 +109,9 @@ _mesa_new_framebuffer(GLcontext *ctx, GLuint name)
if (fb) {
fb->Name = name;
fb->RefCount = 1;
+ fb->_NumColorDrawBuffers = 1;
fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
- fb->_ColorDrawBufferMask[0] = BUFFER_BIT_COLOR0;
+ fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
fb->_ColorReadBufferIndex = BUFFER_COLOR0;
fb->Delete = _mesa_destroy_framebuffer;
@@ -138,16 +140,18 @@ _mesa_initialize_framebuffer(struct gl_framebuffer *fb, const GLvisual *visual)
/* save the visual */
fb->Visual = *visual;
- /* Init glRead/DrawBuffer state */
+ /* Init read/draw renderbuffer state */
if (visual->doubleBufferMode) {
+ fb->_NumColorDrawBuffers = 1;
fb->ColorDrawBuffer[0] = GL_BACK;
- fb->_ColorDrawBufferMask[0] = BUFFER_BIT_BACK_LEFT;
+ fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
fb->ColorReadBuffer = GL_BACK;
fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
}
else {
+ fb->_NumColorDrawBuffers = 1;
fb->ColorDrawBuffer[0] = GL_FRONT;
- fb->_ColorDrawBufferMask[0] = BUFFER_BIT_FRONT_LEFT;
+ fb->_ColorDrawBufferIndexes[0] = BUFFER_FRONT_LEFT;
fb->ColorReadBuffer = GL_FRONT;
fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
}
@@ -660,8 +664,53 @@ _mesa_update_stencil_buffer(GLcontext *ctx,
}
+/*
+ * Example DrawBuffers scenarios:
+ *
+ * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
+ * "gl_FragColor" or program writes to the "result.color" register:
+ *
+ * fragment color output renderbuffer
+ * --------------------- ---------------
+ * color[0] Front, Back
+ *
+ *
+ * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
+ * gl_FragData[i] or program writes to result.color[i] registers:
+ *
+ * fragment color output renderbuffer
+ * --------------------- ---------------
+ * color[0] Front
+ * color[1] Aux0
+ * color[3] Aux1
+ *
+ *
+ * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
+ * gl_FragColor, or fixed function:
+ *
+ * fragment color output renderbuffer
+ * --------------------- ---------------
+ * color[0] Front, Aux0, Aux1
+ *
+ *
+ * In either case, the list of renderbuffers is stored in the
+ * framebuffer->_ColorDrawBuffers[] array and
+ * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
+ * The renderer (like swrast) has to look at the current fragment shader
+ * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
+ * how to map color outputs to renderbuffers.
+ *
+ * Note that these two calls are equivalent (for fixed function fragment
+ * shading anyway):
+ * a) glDrawBuffer(GL_FRONT_AND_BACK); (assuming non-stereo framebuffer)
+ * b) glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
+ */
+
+
+
+
/**
- * Update the list of color drawing renderbuffer pointers.
+ * Update the (derived) list of color drawing renderbuffer pointers.
* Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
* writing colors.
*/
@@ -670,42 +719,23 @@ update_color_draw_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
{
GLuint output;
- /*
- * Fragment programs can write to multiple colorbuffers with
- * the GL_ARB_draw_buffers extension.
- */
- for (output = 0; output < ctx->Const.MaxDrawBuffers; output++) {
- GLbitfield bufferMask = fb->_ColorDrawBufferMask[output];
- GLuint count = 0;
- GLuint i;
- if (!fb->DeletePending) {
- /* We need the inner loop here because glDrawBuffer(GL_FRONT_AND_BACK)
- * can specify writing to two or four color buffers (for example).
- */
- for (i = 0; bufferMask && i < BUFFER_COUNT; i++) {
- const GLuint bufferBit = 1 << i;
- if (bufferBit & bufferMask) {
- struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
- if (rb && rb->Width > 0 && rb->Height > 0) {
- fb->_ColorDrawBuffers[output][count] = rb;
- count++;
- }
- else {
- /*
- _mesa_warning(ctx, "DrawBuffer names a missing buffer!\n");
- */
- }
- bufferMask &= ~bufferBit;
- }
- }
+ /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
+ fb->_ColorDrawBuffers[0] = NULL;
+
+ for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
+ GLint buf = fb->_ColorDrawBufferIndexes[output];
+ if (buf >= 0) {
+ fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
+ }
+ else {
+ fb->_ColorDrawBuffers[output] = NULL;
}
- fb->_NumColorDrawBuffers[output] = count;
}
}
/**
- * Update the color read renderbuffer pointer.
+ * Update the (derived) color read renderbuffer pointer.
* Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
*/
static void
@@ -727,19 +757,51 @@ update_color_read_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
}
+/**
+ * Update a gl_framebuffer's derived state.
+ *
+ * Specifically, update these framebuffer fields:
+ * _ColorDrawBuffers
+ * _NumColorDrawBuffers
+ * _ColorReadBuffer
+ * _DepthBuffer
+ * _StencilBuffer
+ *
+ * If the framebuffer is user-created, make sure it's complete.
+ *
+ * The following functions (at least) can effect framebuffer state:
+ * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
+ * glRenderbufferStorageEXT.
+ */
static void
update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
{
- /* Completeness only matters for user-created framebuffers */
- if (fb->Name != 0) {
- /* XXX: EXT_framebuffer_blit:
- framebuffer must still be complete wrt read/draw? */
+ if (fb->Name == 0) {
+ /* This is a window-system framebuffer */
+ /* Need to update the FB's GL_DRAW_BUFFER state to match the
+ * context state (GL_READ_BUFFER too).
+ */
+ if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
+ _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,
+ ctx->Color.DrawBuffer, NULL);
+ }
+ if (fb->ColorReadBuffer != ctx->Pixel.ReadBuffer) {
+
+ }
+ }
+ else {
+ /* This is a user-created framebuffer.
+ * Completeness only matters for user-created framebuffers.
+ */
_mesa_test_framebuffer_completeness(ctx, fb);
_mesa_update_framebuffer_visual(fb);
}
- /* update_color_draw/read_buffers not needed for
- read/draw only fb, but shouldn't hurt ??? */
+ /* Strictly speaking, we don't need to update the draw-state
+ * if this FB is bound as ctx->ReadBuffer (and conversely, the
+ * read-state if this FB is bound as ctx->DrawBuffer), but no
+ * harm.
+ */
update_color_draw_buffers(ctx, fb);
update_color_read_buffer(ctx, fb);
_mesa_update_depth_buffer(ctx, fb, BUFFER_DEPTH);
@@ -748,28 +810,19 @@ update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
compute_depth_max(fb);
}
+
/**
* Update state related to the current draw/read framebuffers.
- * Specifically, update these framebuffer fields:
- * _ColorDrawBuffers
- * _NumColorDrawBuffers
- * _ColorReadBuffer
- * _DepthBuffer
- * _StencilBuffer
- * If the current framebuffer is user-created, make sure it's complete.
- * The following functions can effect this state: glReadBuffer,
- * glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
- * glRenderbufferStorageEXT.
*/
void
_mesa_update_framebuffer(GLcontext *ctx)
{
- struct gl_framebuffer *fb = ctx->DrawBuffer;
- struct gl_framebuffer *fbread = ctx->ReadBuffer;
+ struct gl_framebuffer *drawFb = ctx->DrawBuffer;
+ struct gl_framebuffer *readFb = ctx->ReadBuffer;
- update_framebuffer(ctx, fb);
- if (fbread != fb)
- update_framebuffer(ctx, fbread);
+ update_framebuffer(ctx, drawFb);
+ if (readFb != drawFb)
+ update_framebuffer(ctx, readFb);
}
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