On Mon, Aug 15, 2011 at 3:43 PM, Ian Romanick <i...@freedesktop.org> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 08/15/2011 11:53 AM, Eric Anholt wrote:
>> From: Brian Paul <bri...@vmware.com>
>>
>> Decompress a texture by drawing quad with the texture.
>> ---
>> src/mesa/drivers/common/meta.c | 200
>> ++++++++++++++++++++++++++++++++++++++++
>> src/mesa/drivers/common/meta.h | 6 +
>> 2 files changed, 206 insertions(+), 0 deletions(-)
>>
>> diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
>> index 19eae42..751f3b6 100644
>> --- a/src/mesa/drivers/common/meta.c
>> +++ b/src/mesa/drivers/common/meta.c
>> @@ -287,6 +287,19 @@ struct gen_mipmap_state
>> GLuint FBO;
>> };
>>
>> +
>> +/**
>> + * State for texture decompression
>> + */
>> +struct decompress_state
>> +{
>> + GLuint ArrayObj;
>> + GLuint VBO, FBO, RBO;
>> + GLint Width, Height;
>> + GLenum RBFormat;
>> +};
>> +
>> +
>> #define MAX_META_OPS_DEPTH 2
>> /**
>> * All per-context meta state.
>> @@ -306,6 +319,7 @@ struct gl_meta_state
>> struct drawpix_state DrawPix; /**< For _mesa_meta_DrawPixels() */
>> struct bitmap_state Bitmap; /**< For _mesa_meta_Bitmap() */
>> struct gen_mipmap_state Mipmap; /**< For _mesa_meta_GenerateMipmap()
>> */
>> + struct decompress_state Decompress; /**< For texture decompression */
>> };
>>
>>
>> @@ -3094,3 +3108,189 @@ _mesa_meta_CopyColorSubTable(struct gl_context
>> *ctx,GLenum target, GLsizei start
>>
>> free(buf);
>> }
>> +
>> +
>> +/**
>> + * Decompress a texture image by drawing a quad with the compressed
>> + * texture and reading the pixels out of the color buffer.
>> + * \param slice which slice of a 3D texture or layer of a 1D/2D texture
>> + * \param destFormat format, ala glReadPixels
>> + * \param destType type, ala glReadPixels
>> + * \param dest destination buffer
>> + * \param destRowLength dest image rowLength (ala GL_PACK_ROW_LENGTH)
>> + */
>> +void
>> +_mesa_meta_decompress_texture_image(struct gl_context *ctx,
>> + struct gl_texture_image *texImage,
>> + GLuint slice,
>> + GLenum destFormat, GLenum destType,
>> + GLvoid *dest, GLint destRowLength)
>> +{
>> + struct decompress_state *decompress = &ctx->Meta->Decompress;
>> + struct gl_texture_object *texObj = texImage->TexObject;
>> + const GLint width = texImage->Width;
>> + const GLint height = texImage->Height;
>> + const GLenum target = texObj->Target;
>> + GLenum faceTarget, rbFormat;
>> + struct vertex {
>> + GLfloat x, y, tex[3];
>> + };
>> + struct vertex verts[4];
>> + GLuint fboDrawSave, fboReadSave;
>> + GLenum destDataType = _mesa_get_format_datatype(texImage->TexFormat);
>> +
>> + if (slice > 0) {
>> + assert(target == GL_TEXTURE_3D ||
>> + target == GL_TEXTURE_2D_ARRAY);
>> + }
>> +
>> + if (target == GL_TEXTURE_CUBE_MAP) {
>> + faceTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + texImage->Face;
>> + }
>> + else {
>> + faceTarget = target;
>> + }
>> +
>> + /* save fbo bindings (not saved by _mesa_meta_begin()) */
>> + fboDrawSave = ctx->DrawBuffer->Name;
>> + fboReadSave = ctx->ReadBuffer->Name;
>> +
>> + _mesa_meta_begin(ctx, META_ALL);
>> +
>> + /* Create/bind FBO/renderbuffer */
>> + if (decompress->FBO == 0) {
>> + _mesa_GenFramebuffersEXT(1, &decompress->FBO);
>> + _mesa_GenRenderbuffersEXT(1, &decompress->RBO);
>> + _mesa_BindFramebufferEXT(GL_FRAMEBUFFER_EXT, decompress->FBO);
>> + _mesa_BindRenderbufferEXT(GL_RENDERBUFFER_EXT, decompress->RBO);
>> + _mesa_FramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
>> + GL_COLOR_ATTACHMENT0_EXT,
>> + GL_RENDERBUFFER_EXT,
>> + decompress->RBO);
>> + }
>> + else {
>> + _mesa_BindFramebufferEXT(GL_FRAMEBUFFER_EXT, decompress->FBO);
>> + }
>> +
>> + if (destDataType == GL_SIGNED_NORMALIZED) {
>> + rbFormat = GL_RGBA32F;
>> + } else {
>> + rbFormat = GL_RGBA;
>> + }
>
> This bit seems odd. Is GL_RGBA32F the right choice? Won't this fail on
> hardware that can do SIGNED_NORMALIZED but not float rendering?
That bit wasn't in my original patch series. I'm not sure if it's
even legal to do a glGetTexImage() of a compressed texture and get
back signed normalized values. I'd have to do some digging through
specs.
-Brian
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