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nv2a: Implement texture LOD bias #2435

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Merged
merged 4 commits into from
Sep 23, 2025
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Merged

nv2a: Implement texture LOD bias #2435

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b8ada79
nv2a: Implement texture LOD bias
abaire Sep 18, 2025
9c9f43c
SQUASHME: CR updates
abaire Sep 19, 2025
ebbb520
SQUASHME: Renamed convert_lod_bias for namespacing purposes and clarity
abaire Sep 19, 2025
ec5ed5e
SQUASHME: Clamp negative LOD bias as well
abaire Sep 19, 2025
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1 change: 1 addition & 0 deletions hw/xbox/nv2a/pgraph/gl/renderer.h
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Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,7 @@ typedef struct TextureBinding {
bool border_color_set;
GLenum gl_target;
GLuint gl_texture;
uint32_t lod_bias;
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nit: Prefer to group filter params

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Done

} TextureBinding;

typedef struct ShaderModuleCacheKey {
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15 changes: 15 additions & 0 deletions hw/xbox/nv2a/pgraph/gl/texture.c
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Expand Up @@ -107,6 +107,15 @@ static bool check_texture_possibly_dirty(NV2AState *d,
return possibly_dirty;
}

static inline float convert_lod_bias(uint32_t lod_bias)
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If implementation is identical between renderers, prefer to have this in common code

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Done.

{
int sign_extended_bias = lod_bias;
if (lod_bias & (1 << 12)) {
sign_extended_bias |= ~NV_PGRAPH_TEXFILTER0_MIPMAP_LOD_BIAS;
}
return (float)sign_extended_bias / 256.f;
}

static void apply_texture_parameters(TextureBinding *binding,
const BasicColorFormatInfo *f,
unsigned int dimensionality,
Expand All @@ -120,6 +129,8 @@ static void apply_texture_parameters(TextureBinding *binding,
unsigned int addru = GET_MASK(address, NV_PGRAPH_TEXADDRESS0_ADDRU);
unsigned int addrv = GET_MASK(address, NV_PGRAPH_TEXADDRESS0_ADDRV);
unsigned int addrp = GET_MASK(address, NV_PGRAPH_TEXADDRESS0_ADDRP);
unsigned int lod_bias =
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nit: Prefer to group filter params

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Done.

GET_MASK(filter, NV_PGRAPH_TEXFILTER0_MIPMAP_LOD_BIAS);

if (f->linear) {
/* somtimes games try to set mipmap min filters on linear textures.
Expand All @@ -146,6 +157,10 @@ static void apply_texture_parameters(TextureBinding *binding,
pgraph_texture_mag_filter_gl_map[mag_filter]);
binding->mag_filter = mag_filter;
}
if (lod_bias != binding->lod_bias) {
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binding->lod_bias not initialized?

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Good catch, done.

binding->lod_bias = lod_bias;
glTexParameterf(binding->gl_target, GL_TEXTURE_LOD_BIAS, convert_lod_bias(lod_bias));
}

/* Texture wrapping */
assert(addru < ARRAY_SIZE(pgraph_texture_addr_gl_map));
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12 changes: 11 additions & 1 deletion hw/xbox/nv2a/pgraph/vk/texture.c
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Expand Up @@ -51,6 +51,15 @@ static VkSamplerAddressMode lookup_texture_address_mode(int idx)
return pgraph_texture_addr_vk_map[idx];
}

static inline float convert_lod_bias(uint32_t lod_bias)
{
int sign_extended_bias = lod_bias;
if (lod_bias & (1 << 12)) {
sign_extended_bias |= ~NV_PGRAPH_TEXFILTER0_MIPMAP_LOD_BIAS;
}
return (float)sign_extended_bias / 256.f;
}

// FIXME: Move to common
// FIXME: We can shrink the size of this structure
// FIXME: Use simple allocator
Expand Down Expand Up @@ -1356,7 +1365,8 @@ static void create_texture(PGRAPHState *pg, int texture_idx)
VK_SAMPLER_MIPMAP_MODE_LINEAR,
.minLod = mipmap_en ? MIN(state.min_mipmap_level, state.levels - 1) : 0.0,
.maxLod = mipmap_en ? MIN(state.max_mipmap_level, state.levels - 1) : 0.0,
.mipLodBias = 0.0,
.mipLodBias = convert_lod_bias(
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Absolute value needs to be clamped to device limits (see VkPhysicalDeviceLimits::maxSamplerLodBias)

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Done, I think; will need to see if my change builds on CI since I can't build VK locally right now.

GET_MASK(filter, NV_PGRAPH_TEXFILTER0_MIPMAP_LOD_BIAS)),
.pNext = sampler_next_struct,
};

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