#include "enums.h"
#include "fbobject.h"
#include "mtypes.h"
+#include "util/bitscan.h"
#define BAD_MASK ~0u
if (_mesa_is_user_fbo(fb)) {
/* A user-created renderbuffer */
- GLuint i;
- for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
- mask |= (BUFFER_BIT_COLOR0 << i);
- }
+ mask = ((1 << ctx->Const.MaxColorAttachments) - 1) << BUFFER_COLOR0;
}
else {
/* A window system framebuffer */
* return -1 for an invalid buffer.
*/
static gl_buffer_index
-read_buffer_enum_to_index(GLenum buffer)
+read_buffer_enum_to_index(const struct gl_context *ctx, GLenum buffer)
{
switch (buffer) {
case GL_FRONT:
return BUFFER_FRONT_LEFT;
case GL_BACK:
+ if (_mesa_is_gles(ctx)) {
+ /* In draw_buffer_enum_to_bitmask, when GLES contexts draw to
+ * GL_BACK with a single-buffered configuration, we actually end
+ * up drawing to the sole front buffer in our internal
+ * representation. For consistency, we must read from that
+ * front left buffer too.
+ */
+ if (!ctx->DrawBuffer->Visual.doubleBufferMode)
+ return BUFFER_FRONT_LEFT;
+ }
return BUFFER_BACK_LEFT;
case GL_RIGHT:
return BUFFER_FRONT_RIGHT;
return BUFFER_FRONT_LEFT;
case GL_AUX0:
return BUFFER_AUX0;
+ case GL_FRONT_AND_BACK:
+ return BUFFER_FRONT_LEFT;
case GL_AUX1:
case GL_AUX2:
case GL_AUX3:
if (buffer >= GL_COLOR_ATTACHMENT8 && buffer <= GL_COLOR_ATTACHMENT31)
return BUFFER_COUNT;
/* error */
- return -1;
+ return BUFFER_NONE;
}
}
+static bool
+is_legal_es3_readbuffer_enum(GLenum buf)
+{
+ return buf == GL_BACK || buf == GL_NONE ||
+ (buf >= GL_COLOR_ATTACHMENT0 && buf <= GL_COLOR_ATTACHMENT31);
+}
/**
- * Called by glDrawBuffer().
+ * Called by glDrawBuffer() and glNamedFramebufferDrawBuffer().
* Specify which renderbuffer(s) to draw into for the first color output.
* <buffer> can name zero, one, two or four renderbuffers!
* \sa _mesa_DrawBuffers
*
* See the GL_EXT_framebuffer_object spec for more info.
*/
-void
-_mesa_draw_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
- GLenum buffer, const char *caller)
+static void
+draw_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
+ GLenum buffer, const char *caller)
{
GLbitfield destMask;
_mesa_DrawBuffer(GLenum buffer)
{
GET_CURRENT_CONTEXT(ctx);
- _mesa_draw_buffer(ctx, ctx->DrawBuffer, buffer, "glDrawBuffer");
+ draw_buffer(ctx, ctx->DrawBuffer, buffer, "glDrawBuffer");
}
else
fb = ctx->WinSysDrawBuffer;
- _mesa_draw_buffer(ctx, fb, buf, "glNamedFramebufferDrawBuffer");
+ draw_buffer(ctx, fb, buf, "glNamedFramebufferDrawBuffer");
}
/**
- * Called by glDrawBuffersARB; specifies the destination color renderbuffers
- * for N fragment program color outputs.
+ * Called by glDrawBuffersARB() and glNamedFramebufferDrawBuffers() to specify
+ * the destination color renderbuffers for N fragment program color outputs.
* \sa _mesa_DrawBuffer
* \param n number of outputs
* \param buffers array [n] of renderbuffer names. Unlike glDrawBuffer, the
* names cannot specify more than one buffer. For example,
- * GL_FRONT_AND_BACK is illegal.
+ * GL_FRONT_AND_BACK is illegal. The only exception is GL_BACK
+ * that is considered special and allowed as far as n is one
+ * since 4.5.
*/
-void
-_mesa_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
- GLsizei n, const GLenum *buffers, const char *caller)
+static void
+draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
+ GLsizei n, const GLenum *buffers, const char *caller)
{
GLuint output;
GLbitfield usedBufferMask, supportedMask;
/* complicated error checking... */
for (output = 0; output < n; output++) {
- /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL 3.0
+ destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
+
+ /* From the OpenGL 3.0 specification, page 258:
+ * "Each buffer listed in bufs must be one of the values from tables
+ * 4.5 or 4.6. Otherwise, an INVALID_ENUM error is generated.
+ */
+ if (destMask[output] == BAD_MASK) {
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
+ caller, _mesa_enum_to_string(buffers[output]));
+ return;
+ }
+
+ /* From the OpenGL 4.5 specification, page 493 (page 515 of the PDF)
+ * "An INVALID_ENUM error is generated if any value in bufs is FRONT,
+ * LEFT, RIGHT, or FRONT_AND_BACK . This restriction applies to both
+ * the default framebuffer and framebuffer objects, and exists because
+ * these constants may themselves refer to multiple buffers, as shown
+ * in table 17.4."
+ *
+ * And on page 492 (page 514 of the PDF):
+ * "If the default framebuffer is affected, then each of the constants
+ * must be one of the values listed in table 17.6 or the special value
+ * BACK. When BACK is used, n must be 1 and color values are written
+ * into the left buffer for single-buffered contexts, or into the back
+ * left buffer for double-buffered contexts."
+ *
+ * Note "special value BACK". GL_BACK also refers to multiple buffers,
+ * but it is consider a special case here. This is a change on 4.5. For
+ * OpenGL 4.x we check that behaviour. For any previous version we keep
+ * considering it wrong (as INVALID_ENUM).
+ */
+ if (_mesa_bitcount(destMask[output]) > 1) {
+ if (_mesa_is_winsys_fbo(fb) && ctx->Version >= 40 &&
+ buffers[output] == GL_BACK) {
+ if (n != 1) {
+ _mesa_error(ctx, GL_INVALID_OPERATION, "%s(with GL_BACK n must be 1)",
+ caller);
+ return;
+ }
+ } else {
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
+ caller, _mesa_enum_to_string(buffers[output]));
+ return;
+ }
+ }
+
+ /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0
* specification says:
*
- * "Each buffer listed in bufs must be BACK, NONE, or one of the values
- * from table 4.3 (NONE, COLOR_ATTACHMENTi)"
+ * "If the GL is bound to a draw framebuffer object, the ith buffer
+ * listed in bufs must be COLOR_ATTACHMENTi or NONE . Specifying a
+ * buffer out of order, BACK , or COLOR_ATTACHMENTm where m is greater
+ * than or equal to the value of MAX_- COLOR_ATTACHMENTS , will
+ * generate the error INVALID_OPERATION .
*/
- if (_mesa_is_gles3(ctx) && buffers[output] != GL_NONE &&
- buffers[output] != GL_BACK &&
+ if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(fb) &&
+ buffers[output] != GL_NONE &&
(buffers[output] < GL_COLOR_ATTACHMENT0 ||
buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) {
- _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffers(buffer)");
+ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)");
return;
}
return;
}
- destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
-
- /* From the OpenGL 3.0 specification, page 258:
- * "Each buffer listed in bufs must be one of the values from tables
- * 4.5 or 4.6. Otherwise, an INVALID_ENUM error is generated.
- */
- if (destMask[output] == BAD_MASK) {
- _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
- caller, _mesa_enum_to_string(buffers[output]));
- return;
- }
-
- /* From the OpenGL 4.0 specification, page 256:
- * "For both the default framebuffer and framebuffer objects, the
- * constants FRONT, BACK, LEFT, RIGHT, and FRONT_AND_BACK are not
- * valid in the bufs array passed to DrawBuffers, and will result in
- * the error INVALID_ENUM. This restriction is because these
- * constants may themselves refer to multiple buffers, as shown in
- * table 4.4."
- * Previous versions of the OpenGL specification say INVALID_OPERATION,
- * but the Khronos conformance tests expect INVALID_ENUM.
- */
- if (_mesa_bitcount(destMask[output]) > 1) {
- _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
- caller, _mesa_enum_to_string(buffers[output]));
- return;
- }
-
/* From the OpenGL 3.0 specification, page 259:
* "If the GL is bound to the default framebuffer and DrawBuffers is
* supplied with a constant (other than NONE) that does not indicate
_mesa_DrawBuffers(GLsizei n, const GLenum *buffers)
{
GET_CURRENT_CONTEXT(ctx);
- _mesa_draw_buffers(ctx, ctx->DrawBuffer, n, buffers, "glDrawBuffers");
+ draw_buffers(ctx, ctx->DrawBuffer, n, buffers, "glDrawBuffers");
}
else
fb = ctx->WinSysDrawBuffer;
- _mesa_draw_buffers(ctx, fb, n, bufs, "glNamedFramebufferDrawBuffers");
+ draw_buffers(ctx, fb, n, bufs, "glNamedFramebufferDrawBuffers");
}
/**
- * Helper function to set the GL_DRAW_BUFFER state in the context and
- * current FBO. Called via glDrawBuffer(), glDrawBuffersARB()
+ * Helper function to set the GL_DRAW_BUFFER state for the given context and
+ * FBO. Called via glDrawBuffer(), glDrawBuffersARB()
*
* All error checking will have been done prior to calling this function
* so nothing should go wrong at this point.
if (n > 0 && _mesa_bitcount(destMask[0]) > 1) {
GLuint count = 0, destMask0 = destMask[0];
while (destMask0) {
- GLint bufIndex = ffs(destMask0) - 1;
+ const int bufIndex = u_bit_scan(&destMask0);
if (fb->_ColorDrawBufferIndexes[count] != bufIndex) {
updated_drawbuffers(ctx, fb);
fb->_ColorDrawBufferIndexes[count] = bufIndex;
}
count++;
- destMask0 &= ~(1 << bufIndex);
}
fb->ColorDrawBuffer[0] = buffers[0];
fb->_NumColorDrawBuffers = count;
/**
* Like \sa _mesa_drawbuffers(), this is a helper function for setting
- * GL_READ_BUFFER state in the context and current FBO.
+ * GL_READ_BUFFER state for the given context and FBO.
+ * Note that all error checking should have been done before calling
+ * this function.
* \param ctx the rendering context
+ * \param fb the framebuffer object to update
* \param buffer GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc.
* \param bufferIndex the numerical index corresponding to 'buffer'
*/
/**
- * Called by glReadBuffer to set the source renderbuffer for reading pixels.
+ * Called by glReadBuffer and glNamedFramebufferReadBuffer to set the source
+ * renderbuffer for reading pixels.
* \param mode color buffer such as GL_FRONT, GL_BACK, etc.
*/
-void
-_mesa_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
- GLenum buffer, const char *caller)
+static void
+read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
+ GLenum buffer, const char *caller)
{
GLbitfield supportedMask;
gl_buffer_index srcBuffer;
if (buffer == GL_NONE) {
/* This is legal--it means that no buffer should be bound for reading. */
- srcBuffer = -1;
+ srcBuffer = BUFFER_NONE;
}
else {
/* general case / window-system framebuffer */
- srcBuffer = read_buffer_enum_to_index(buffer);
- if (srcBuffer == -1) {
+ if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer))
+ srcBuffer = BUFFER_NONE;
+ else
+ srcBuffer = read_buffer_enum_to_index(ctx, buffer);
+
+ if (srcBuffer == BUFFER_NONE) {
_mesa_error(ctx, GL_INVALID_ENUM,
"%s(invalid buffer %s)", caller,
_mesa_enum_to_string(buffer));
_mesa_ReadBuffer(GLenum buffer)
{
GET_CURRENT_CONTEXT(ctx);
- _mesa_read_buffer(ctx, ctx->ReadBuffer, buffer, "glReadBuffer");
+ read_buffer(ctx, ctx->ReadBuffer, buffer, "glReadBuffer");
}
else
fb = ctx->WinSysReadBuffer;
- _mesa_read_buffer(ctx, fb, src, "glNamedFramebufferReadBuffer");
+ read_buffer(ctx, fb, src, "glNamedFramebufferReadBuffer");
}
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