[Mesa-dev] [PATCH v3 12/28] mesa: use _mesa_format_convert to implement glReadPixels.
Iago Toral Quiroga
itoral at igalia.com
Tue Dec 9 04:07:21 PST 2014
---
src/mesa/main/readpix.c | 321 +++++++++++++++++++++++++++---------------------
1 file changed, 179 insertions(+), 142 deletions(-)
diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index b09cf54..1124aa7 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -39,6 +39,8 @@
#include "state.h"
#include "glformats.h"
#include "fbobject.h"
+#include "format_utils.h"
+#include "pixeltransfer.h"
/**
@@ -405,174 +407,209 @@ read_stencil_pixels( struct gl_context *ctx,
ctx->Driver.UnmapRenderbuffer(ctx, rb);
}
-
-/**
- * Try to do glReadPixels of RGBA data using swizzle.
- * \return GL_TRUE if successful, GL_FALSE otherwise (use the slow path)
+/*
+ * Read R, G, B, A, RGB, L, or LA pixels.
*/
-static GLboolean
-read_rgba_pixels_swizzle(struct gl_context *ctx,
- GLint x, GLint y,
- GLsizei width, GLsizei height,
- GLenum format, GLenum type,
- GLvoid *pixels,
- const struct gl_pixelstore_attrib *packing)
+static void
+read_rgba_pixels( struct gl_context *ctx,
+ GLint x, GLint y,
+ GLsizei width, GLsizei height,
+ GLenum format, GLenum type, GLvoid *pixels,
+ const struct gl_pixelstore_attrib *packing )
{
- struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
+ GLbitfield transferOps;
+ bool dst_is_integer, dst_is_luminance, needs_rebase;
+ int dst_stride, src_stride, rb_stride;
+ uint32_t dst_format, src_format;
GLubyte *dst, *map;
- int dstStride, stride, j;
- GLboolean swizzle_rb = GL_FALSE, copy_xrgb = GL_FALSE;
-
- /* XXX we could check for other swizzle/special cases here as needed */
- if (rb->Format == MESA_FORMAT_R8G8B8A8_UNORM &&
- format == GL_BGRA &&
- type == GL_UNSIGNED_INT_8_8_8_8_REV &&
- !ctx->Pack.SwapBytes) {
- swizzle_rb = GL_TRUE;
- }
- else if (rb->Format == MESA_FORMAT_B8G8R8X8_UNORM &&
- format == GL_BGRA &&
- type == GL_UNSIGNED_INT_8_8_8_8_REV &&
- !ctx->Pack.SwapBytes) {
- copy_xrgb = GL_TRUE;
- }
- else {
- return GL_FALSE;
- }
+ mesa_format rb_format;
+ bool needs_rgba;
+ void *rgba, *src;
+ uint8_t rebase_swizzle[4];
+ struct gl_framebuffer *fb = ctx->ReadBuffer;
+ struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
- dstStride = _mesa_image_row_stride(packing, width, format, type);
+ if (!rb)
+ return;
+
+ transferOps = get_readpixels_transfer_ops(ctx, rb->Format, format, type,
+ GL_FALSE);
+ /* Describe the dst format */
+ dst_is_integer = _mesa_is_enum_format_integer(format);
+ dst_stride = _mesa_image_row_stride(packing, width, format, type);
+ dst_format = _mesa_format_from_format_and_type(format, type);
+ dst_is_luminance = format == GL_LUMINANCE || format == GL_LUMINANCE_ALPHA;
dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
- format, type, 0, 0);
+ format, type, 0, 0);
+ /* Map the source render buffer */
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
- &map, &stride);
+ &map, &rb_stride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
- return GL_TRUE; /* don't bother trying the slow path */
+ return;
}
+ rb_format = _mesa_get_srgb_format_linear(rb->Format);
- if (swizzle_rb) {
- /* swap R/B */
- for (j = 0; j < height; j++) {
- int i;
- for (i = 0; i < width; i++) {
- GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
- GLuint pixel = map4[i];
- dst4[i] = (pixel & 0xff00ff00)
- | ((pixel & 0x00ff0000) >> 16)
- | ((pixel & 0x000000ff) << 16);
- }
- dst += dstStride;
- map += stride;
- }
- } else if (copy_xrgb) {
- /* convert xrgb -> argb */
- for (j = 0; j < height; j++) {
- GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
- int i;
- for (i = 0; i < width; i++) {
- dst4[i] = map4[i] | 0xff000000; /* set A=0xff */
- }
- dst += dstStride;
- map += stride;
- }
+ /*
+ * Depending on the base formats involved in the conversion we might need to
+ * rebase some values, so for these formats we compute a rebase swizzle.
+ */
+ if (rb->_BaseFormat == GL_LUMINANCE || rb->_BaseFormat == GL_INTENSITY) {
+ needs_rebase = true;
+ rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
+ rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
+ rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
+ rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_ONE;
+ } else if (rb->_BaseFormat == GL_LUMINANCE_ALPHA) {
+ needs_rebase = true;
+ rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
+ rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
+ rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
+ rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_W;
+ } else if (_mesa_get_format_base_format(rb_format) != rb->_BaseFormat) {
+ needs_rebase =
+ _mesa_compute_rgba2base2rgba_component_mapping(rb->_BaseFormat,
+ rebase_swizzle);
+ } else {
+ needs_rebase = false;
}
- ctx->Driver.UnmapRenderbuffer(ctx, rb);
-
- return GL_TRUE;
-}
-
-static void
-slow_read_rgba_pixels( struct gl_context *ctx,
- GLint x, GLint y,
- GLsizei width, GLsizei height,
- GLenum format, GLenum type,
- GLvoid *pixels,
- const struct gl_pixelstore_attrib *packing,
- GLbitfield transferOps )
-{
- struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
- const mesa_format rbFormat = _mesa_get_srgb_format_linear(rb->Format);
- void *rgba;
- GLubyte *dst, *map;
- int dstStride, stride, j;
- GLboolean dst_is_integer = _mesa_is_enum_format_integer(format);
- GLboolean dst_is_uint = _mesa_is_format_unsigned(rbFormat);
-
- dstStride = _mesa_image_row_stride(packing, width, format, type);
- dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
- format, type, 0, 0);
-
- ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
- &map, &stride);
- if (!map) {
- _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
- return;
- }
+ /* Since _mesa_format_convert does not handle transferOps we need to handle
+ * them before we call the function. This requires to convert to RGBA float
+ * first so we can call _mesa_apply_rgba_transfer_ops. If the dst format is
+ * integer transferOps do not apply.
+ *
+ * Converting to luminance also requires converting to RGBA first, so we can
+ * then compute luminance values as L=R+G+B. Notice that this is different
+ * from GetTexImage, where we compute L=R.
+ */
+ assert(!transferOps || (transferOps && !dst_is_integer));
- rgba = malloc(width * MAX_PIXEL_BYTES);
- if (!rgba)
- goto done;
+ needs_rgba = transferOps || dst_is_luminance;
+ rgba = NULL;
+ if (needs_rgba) {
+ uint32_t rgba_format;
+ int rgba_stride;
+ bool need_convert;
- for (j = 0; j < height; j++) {
+ /* Convert to RGBA float or int/uint depending on the type of the dst. */
if (dst_is_integer) {
- _mesa_unpack_uint_rgba_row(rbFormat, width, map, (GLuint (*)[4]) rgba);
- _mesa_rebase_rgba_uint(width, (GLuint (*)[4]) rgba,
- rb->_BaseFormat);
- if (dst_is_uint) {
- _mesa_pack_rgba_span_from_uints(ctx, width, (GLuint (*)[4]) rgba, format,
- type, dst);
+ GLboolean src_is_uint = _mesa_is_format_unsigned(rb_format);
+ if (src_is_uint) {
+ rgba_format = RGBA8888_UINT;
+ rgba_stride = width * 4 * sizeof(GLuint);
} else {
- _mesa_pack_rgba_span_from_ints(ctx, width, (GLint (*)[4]) rgba, format,
- type, dst);
+ rgba_format = RGBA8888_INT;
+ rgba_stride = width * 4 * sizeof(GLint);
}
} else {
- _mesa_unpack_rgba_row(rbFormat, width, map, (GLfloat (*)[4]) rgba);
- _mesa_rebase_rgba_float(width, (GLfloat (*)[4]) rgba,
- rb->_BaseFormat);
- _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba, format,
- type, dst, packing, transferOps);
+ rgba_format = RGBA8888_FLOAT;
+ rgba_stride = width * 4 * sizeof(GLfloat);
}
- dst += dstStride;
- map += stride;
- }
-
- free(rgba);
-
-done:
- ctx->Driver.UnmapRenderbuffer(ctx, rb);
-}
-/*
- * Read R, G, B, A, RGB, L, or LA pixels.
- */
-static void
-read_rgba_pixels( struct gl_context *ctx,
- GLint x, GLint y,
- GLsizei width, GLsizei height,
- GLenum format, GLenum type, GLvoid *pixels,
- const struct gl_pixelstore_attrib *packing )
-{
- GLbitfield transferOps;
- struct gl_framebuffer *fb = ctx->ReadBuffer;
- struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
+ /* If we are lucky and the dst format matches the RGBA format we need to
+ * convert to, then we can convert directly into the dst buffer and avoid
+ * the final conversion/copy from the rgba buffer to the dst buffer.
+ */
+ if (dst_format == rgba_format) {
+ need_convert = false;
+ rgba = dst;
+ } else {
+ need_convert = true;
+ rgba = malloc(height * rgba_stride);
+ if (!rgba) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+ goto done_unmap;
+ }
+ }
- if (!rb)
- return;
+ /* Convert to RGBA now */
+ _mesa_format_convert(rgba, rgba_format, rgba_stride,
+ map, rb_format, rb_stride,
+ width, height,
+ needs_rebase ? rebase_swizzle : NULL);
+
+ /* Handle transfer ops if necessary */
+ if (transferOps)
+ _mesa_apply_rgba_transfer_ops(ctx, transferOps, width * height, rgba);
+
+ /* If we had to rebase, we have already taken care of that */
+ needs_rebase = false;
+
+ /* If we were lucky and our RGBA conversion matches the dst format, then
+ * we are done.
+ */
+ if (!need_convert)
+ goto done_swap;
+
+ /* Otherwise, we need to convert from RGBA to dst next */
+ src = rgba;
+ src_format = rgba_format;
+ src_stride = rgba_stride;
+ } else {
+ /* No RGBA conversion needed, convert directly to dst */
+ src = map;
+ src_format = rb_format;
+ src_stride = rb_stride;
+ }
- transferOps = get_readpixels_transfer_ops(ctx, rb->Format, format, type,
- GL_FALSE);
+ /* Do the conversion.
+ *
+ * If the dst format is Luminance, we need to do the conversion by computing
+ * L=R+G+B values.
+ */
+ if (format != GL_LUMINANCE && format != GL_LUMINANCE_ALPHA) {
+ _mesa_format_convert(dst, dst_format, dst_stride,
+ src, src_format, src_stride,
+ width, height,
+ needs_rebase ? rebase_swizzle : NULL);
+ } else if (!dst_is_integer) {
+ /* Compute float Luminance values from RGBA float */
+ int luminance_stride, luminance_bytes;
+ void *luminance;
+ uint32_t luminance_format;
+
+ luminance_stride = width * sizeof(GL_FLOAT);
+ if (format == GL_LUMINANCE_ALPHA)
+ luminance_stride *= 2;
+ luminance_bytes = height * luminance_stride;
+ luminance = malloc(luminance_bytes);
+ if (!luminance) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+ free(rgba);
+ goto done_unmap;
+ }
+ _mesa_pack_luminance_from_rgba_float(width * height, src,
+ luminance, format, transferOps);
+
+ /* Convert from Luminance float to dst (this will hadle type conversion
+ * from float to the type of dst if necessary)
+ */
+ luminance_format = _mesa_format_from_format_and_type(format, GL_FLOAT);
+ _mesa_format_convert(dst, dst_format, dst_stride,
+ luminance, luminance_format, luminance_stride,
+ width, height, NULL);
+ } else {
+ _mesa_pack_luminance_from_rgba_integer(width * height, src, dst, format);
+ }
- /* Try the optimized paths first. */
- if (!transferOps &&
- read_rgba_pixels_swizzle(ctx, x, y, width, height,
- format, type, pixels, packing)) {
- return;
+ if (rgba)
+ free(rgba);
+
+done_swap:
+ /* Handle byte swapping if required */
+ if (packing->SwapBytes) {
+ int components = _mesa_components_in_format(format);
+ GLint swapSize = _mesa_sizeof_packed_type(type);
+ if (swapSize == 2)
+ _mesa_swap2((GLushort *) dst, width * height * components);
+ else if (swapSize == 4)
+ _mesa_swap4((GLuint *) dst, width * height * components);
}
- slow_read_rgba_pixels(ctx, x, y, width, height,
- format, type, pixels, packing, transferOps);
+done_unmap:
+ ctx->Driver.UnmapRenderbuffer(ctx, rb);
}
/**
--
1.9.1
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