LibGL+LibSoftGPU: Add support for 8-bit luminance (+ alpha) textures

Used by Half-Life for single colour textures. The alpha variant is
especially used for UI textures.
This commit is contained in:
Luke Wilde 2022-01-15 10:11:27 +00:00 committed by Andreas Kling
parent 6e37487477
commit c6a0365c58
Notes: sideshowbarker 2024-07-17 20:51:56 +09:00
3 changed files with 43 additions and 1 deletions

View File

@ -239,7 +239,9 @@ extern "C" {
#define GL_RGB 0x1907
#define GL_RGBA 0x1908
#define GL_LUMINANCE 0x1909
#define GL_LUMINANCE8 0x8040
#define GL_LUMINANCE_ALPHA 0x190A
#define GL_LUMINANCE8_ALPHA8 0x8045
#define GL_BGR 0x190B
#define GL_BGRA 0x190C
#define GL_BITMAP 0x1A00

View File

@ -915,7 +915,7 @@ void SoftwareGLContext::gl_tex_image_2d(GLenum target, GLint level, GLint intern
internal_format = GL_RGBA;
// We only support symbolic constants for now
RETURN_WITH_ERROR_IF(!(internal_format == GL_RGB || internal_format == GL_RGBA), GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(!(internal_format == GL_RGB || internal_format == GL_RGBA || internal_format == GL_LUMINANCE8 || internal_format == GL_LUMINANCE8_ALPHA8), GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(!(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_SHORT_5_6_5), GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(level < 0 || level > Texture2D::LOG2_MAX_TEXTURE_SIZE, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(width < 0 || height < 0 || width > (2 + Texture2D::MAX_TEXTURE_SIZE) || height > (2 + Texture2D::MAX_TEXTURE_SIZE), GL_INVALID_VALUE);
@ -941,6 +941,14 @@ void SoftwareGLContext::gl_tex_image_2d(GLenum target, GLint level, GLint intern
device_format = SoftGPU::ImageFormat::RGBA8888;
break;
case GL_LUMINANCE8:
device_format = SoftGPU::ImageFormat::L8;
break;
case GL_LUMINANCE8_ALPHA8:
device_format = SoftGPU::ImageFormat::L8A8;
break;
default:
VERIFY_NOT_REACHED();
}

View File

@ -16,12 +16,17 @@ enum class ImageFormat {
BGR888,
RGBA8888,
BGRA8888,
L8,
L8A8,
};
inline static constexpr size_t element_size(ImageFormat format)
{
switch (format) {
case ImageFormat::L8:
return 1;
case ImageFormat::RGB565:
case ImageFormat::L8A8:
return 2;
case ImageFormat::RGB888:
case ImageFormat::BGR888:
@ -83,6 +88,26 @@ inline static FloatVector4 unpack_color(void const* ptr, ImageFormat format)
1.0f
};
}
case ImageFormat::L8: {
auto luminance = *reinterpret_cast<u8 const*>(ptr);
auto clamped_luminance = luminance * one_over_255;
return {
clamped_luminance,
clamped_luminance,
clamped_luminance,
1.0f,
};
}
case ImageFormat::L8A8: {
auto luminance_and_alpha = reinterpret_cast<u8 const*>(ptr);
auto clamped_luminance = luminance_and_alpha[0] * one_over_255;
return {
clamped_luminance,
clamped_luminance,
clamped_luminance,
luminance_and_alpha[1] * one_over_255,
};
}
default:
VERIFY_NOT_REACHED();
}
@ -115,6 +140,13 @@ inline static void pack_color(FloatVector4 const& color, void* ptr, ImageFormat
case ImageFormat::RGB565:
*reinterpret_cast<u16*>(ptr) = (r & 0x1f) | ((g & 0x3f) << 5) | ((b & 0x1f) << 11);
return;
case ImageFormat::L8:
*reinterpret_cast<u8*>(ptr) = r;
return;
case ImageFormat::L8A8:
reinterpret_cast<u8*>(ptr)[0] = r;
reinterpret_cast<u8*>(ptr)[1] = a;
return;
default:
VERIFY_NOT_REACHED();
}