[Mesa-dev] [PATCH 1/2] _mesa_meta_GenerateMipmap: Support all texture targets by generating shaders at runtime

[Brian Paul]

On 09/11/2012 01:56 AM, Ian Romanick wrote:
> On 09/05/2012 05:42 AM, Anuj Phogat wrote:
>> glsl path of _mesa_meta_GenerateMipmap() function would require
>> different fragment
>> shaders depending on the texture target. This patch adds the code to
>> generate
>> appropriate fragment shader programs at run time.
>> Fixes https://bugs.freedesktop.org/show_bug.cgi?id=54296
>>
>> NOTE: This is a candidate for stable branches.
>>
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>> src/mesa/drivers/common/meta.c | 100
>> +++++++++++++++++++++++++++++++++++----
>> 1 files changed, 89 insertions(+), 11 deletions(-)
>>
>> diff --git a/src/mesa/drivers/common/meta.c
>> b/src/mesa/drivers/common/meta.c
>> index 36672a7..7d701f4 100644
>> --- a/src/mesa/drivers/common/meta.c
>> +++ b/src/mesa/drivers/common/meta.c
>> @@ -286,6 +286,15 @@ struct gen_mipmap_state
>> GLuint IntegerShaderProg;
>> };
>>
>> +/**
>> + * State for GLSL texture sampler which is used to generate fragment
>> + * shader in _mesa_meta_generate_mipmap().
>> + */
>> +struct glsl_sampler {
>> + const char *type;
>> + const char *func;
>> + const char *texcoords;
>> +};
>>
>> /**
>> * State for texture decompression
>> @@ -2974,7 +2983,7 @@ setup_texture_coords(GLenum faceTarget,
>>
>> static void
>> setup_ff_generate_mipmap(struct gl_context *ctx,
>> - struct gen_mipmap_state *mipmap)
>> + struct gen_mipmap_state *mipmap)
>> {
>> struct vertex {
>> GLfloat x, y, tex[3];
>> @@ -3004,12 +3013,53 @@ setup_ff_generate_mipmap(struct gl_context
>> *ctx,
>>
>>
>> static void
>> +setup_texture_sampler(GLenum target, struct glsl_sampler *sampler)
>> +{
>> + switch(target) {
>> + case GL_TEXTURE_1D:
>> + sampler->type = "sampler1D";
>> + sampler->func = "texture1D";
>> + sampler->texcoords = "texCoords.x";
>> + break;
>> + case GL_TEXTURE_2D:
>> + sampler->type = "sampler2D";
>> + sampler->func = "texture2D";
>> + sampler->texcoords = "texCoords.xy";
>> + break;
>> + case GL_TEXTURE_3D:
>> + sampler->type = "sampler3D";
>> + sampler->func = "texture3D";
>> + sampler->texcoords = "texCoords";
>> + break;
>> + case GL_TEXTURE_CUBE_MAP:
>> + sampler->type = "samplerCube";
>> + sampler->func = "textureCube";
>> + sampler->texcoords = "texCoords";
>> + break;
>> + case GL_TEXTURE_1D_ARRAY:
>> + sampler->type = "sampler1DARRAY";
>> + sampler->texcoords = "texCoords.xy";
>> + break;
>> + case GL_TEXTURE_2D_ARRAY:
>> + sampler->type = "sampler2DARRAY";
>> + sampler->texcoords = "texCoords";
>> + break;
>> + default:
>> + /* unexpected texture target */
>> + return;
>> + }
>> +}
>> +
>> +
>> +static void
>> setup_glsl_generate_mipmap(struct gl_context *ctx,
>> - struct gen_mipmap_state *mipmap)
>> + struct gen_mipmap_state *mipmap,
>> + GLenum target)
>> {
>> struct vertex {
>> GLfloat x, y, tex[3];
>> };
>> + struct glsl_sampler sampler;
>>
>> static const char *vs_source =
>> "attribute vec2 position;\n"
>> @@ -3020,14 +3070,17 @@ setup_glsl_generate_mipmap(struct gl_context
>> *ctx,
>> " texCoords = textureCoords;\n"
>> " gl_Position = vec4(position, 0.0, 1.0);\n"
>> "}\n";
>> - static const char *fs_source =
>> - "uniform sampler2D tex2d;\n"
>> + static const char *fs_template =
>> + "#define SAMPLER_TYPE %s\n"
>> + "#define SAMPLER_FUNCTION %s\n"
>> + "#define TEX_COORDS %s\n"
>
> Since each of these is only used once, why use the extra #defines? I
> believe we can use $ to force the arguments to have the same order.
>
> static const char *fs_template =
> "uniform %1$s texSampler;\n"
> "varying vec3 texCoords;\n"
> "void main()\n"
> "{\n"
> " gl_FragColor = %2$s(texSampler, %3$s);\n"
> "}\n";
>
> This works like the {0} formatting in Python.
>
> Brian, do you know if this is supported on Windows?

I don't think so.  I see no mention of it in the MSDN docs and the 
Linux man page says "The C99 standard does not include the style using 
  '$', which comes from the Single Unix Specification."

To be honest, I wasn't even aware of the $ syntax until you wrote this.

-Brian