Support 16-Bit HDR textures (#3220)

* Support 16-Bit HDR textures

* Fix build on emscripten

* Move helper functions

1 files changed, 29 insertions, 10 deletions

diff --git a/src/rlgl.h b/src/rlgl.h
index 470295b0..717fa59f 100644
--- a/src/rlgl.h
+++ b/src/rlgl.h
@@ -419,6 +419,9 @@ typedef enum {
     RL_PIXELFORMAT_UNCOMPRESSED_R32,               // 32 bpp (1 channel - float)
     RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32,         // 32*3 bpp (3 channels - float)
     RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32,      // 32*4 bpp (4 channels - float)
+    RL_PIXELFORMAT_UNCOMPRESSED_R16,               // 16 bpp (1 channel - half float)
+    RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16,         // 16*3 bpp (3 channels - half float)
+    RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16,      // 16*4 bpp (4 channels - half float)
     RL_PIXELFORMAT_COMPRESSED_DXT1_RGB,            // 4 bpp (no alpha)
     RL_PIXELFORMAT_COMPRESSED_DXT1_RGBA,           // 4 bpp (1 bit alpha)
     RL_PIXELFORMAT_COMPRESSED_DXT3_RGBA,           // 8 bpp
@@ -1006,6 +1009,7 @@ typedef struct rlglData {
         bool texDepth;                      // Depth textures supported (GL_ARB_depth_texture, GL_OES_depth_texture)
         bool texDepthWebGL;                 // Depth textures supported WebGL specific (GL_WEBGL_depth_texture)
         bool texFloat32;                    // float textures support (32 bit per channel) (GL_OES_texture_float)
+        bool texFloat16;                    // half float textures support (16 bit per channel) (GL_OES_texture_half_float)
         bool texCompDXT;                    // DDS texture compression support (GL_EXT_texture_compression_s3tc, GL_WEBGL_compressed_texture_s3tc, GL_WEBKIT_WEBGL_compressed_texture_s3tc)
         bool texCompETC1;                   // ETC1 texture compression support (GL_OES_compressed_ETC1_RGB8_texture, GL_WEBGL_compressed_texture_etc1)
         bool texCompETC2;                   // ETC2/EAC texture compression support (GL_ARB_ES3_compatibility)
@@ -2189,6 +2193,7 @@ void rlLoadExtensions(void *loader)
     RLGL.ExtSupported.instancing = (GLAD_GL_EXT_draw_instanced && GLAD_GL_ARB_instanced_arrays);
     RLGL.ExtSupported.texNPOT = GLAD_GL_ARB_texture_non_power_of_two;
     RLGL.ExtSupported.texFloat32 = GLAD_GL_ARB_texture_float;
+    RLGL.ExtSupported.texFloat16 = GLAD_GL_ARB_texture_float;
     RLGL.ExtSupported.texDepth = GLAD_GL_ARB_depth_texture;
     RLGL.ExtSupported.maxDepthBits = 32;
     RLGL.ExtSupported.texAnisoFilter = GLAD_GL_EXT_texture_filter_anisotropic;
@@ -2200,6 +2205,7 @@ void rlLoadExtensions(void *loader)
     RLGL.ExtSupported.instancing = true;
     RLGL.ExtSupported.texNPOT = true;
     RLGL.ExtSupported.texFloat32 = true;
+    RLGL.ExtSupported.texFloat16 = true;
     RLGL.ExtSupported.texDepth = true;
     RLGL.ExtSupported.maxDepthBits = 32;
     RLGL.ExtSupported.texAnisoFilter = true;
@@ -2224,6 +2230,7 @@ void rlLoadExtensions(void *loader)
     RLGL.ExtSupported.instancing = true;
     RLGL.ExtSupported.texNPOT = true;
     RLGL.ExtSupported.texFloat32 = true;
+    RLGL.ExtSupported.texFloat16 = true;
     RLGL.ExtSupported.texDepth = true;
     RLGL.ExtSupported.texDepthWebGL = true;
     RLGL.ExtSupported.maxDepthBits = 24;
@@ -2320,6 +2327,7 @@ void rlLoadExtensions(void *loader)
 
         // Check texture float support
         if (strcmp(extList[i], (const char *)"GL_OES_texture_float") == 0) RLGL.ExtSupported.texFloat32 = true;
+        if (strcmp(extList[i], (const char *)"GL_OES_texture_half_float") == 0) RLGL.ExtSupported.texFloat16 = true;
 
         // Check depth texture support
         if (strcmp(extList[i], (const char *)"GL_OES_depth_texture") == 0) RLGL.ExtSupported.texDepth = true;
@@ -3163,13 +3171,9 @@ unsigned int rlLoadTextureCubemap(const void *data, int size, int format)
             {
                 if (format < RL_PIXELFORMAT_COMPRESSED_DXT1_RGB)
                 {
-                    if (format == RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32)
-                    {
-                        // Instead of using a sized internal texture format (GL_RGB16F, GL_RGB32F), we let the driver to choose the better format for us (GL_RGB)
-                        if (RLGL.ExtSupported.texFloat32) glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, size, size, 0, GL_RGB, GL_FLOAT, NULL);
-                        else TRACELOG(RL_LOG_WARNING, "TEXTURES: Cubemap requested format not supported");
-                    }
-                    else if ((format == RL_PIXELFORMAT_UNCOMPRESSED_R32) || (format == RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32)) TRACELOG(RL_LOG_WARNING, "TEXTURES: Cubemap requested format not supported");
+                    if ((format == RL_PIXELFORMAT_UNCOMPRESSED_R32) || (format == RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32)
+                            || (format == RL_PIXELFORMAT_UNCOMPRESSED_R16) || (format == RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16))
+                        TRACELOG(RL_LOG_WARNING, "TEXTURES: Cubemap requested format not supported");
                     else glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, glInternalFormat, size, size, 0, glFormat, glType, NULL);
                 }
                 else TRACELOG(RL_LOG_WARNING, "TEXTURES: Empty cubemap creation does not support compressed format");
@@ -3256,10 +3260,16 @@ void rlGetGlTextureFormats(int format, unsigned int *glInternalFormat, unsigned
         case RL_PIXELFORMAT_UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_R32F_EXT; *glFormat = GL_RED_EXT; *glType = GL_FLOAT; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB32F_EXT; *glFormat = GL_RGB; *glType = GL_FLOAT; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA32F_EXT; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_R16F_EXT; *glFormat = GL_RED_EXT; *glType = GL_HALF_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGB16F_EXT; *glFormat = GL_RGB; *glType = GL_HALF_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGBA16F_EXT; *glFormat = GL_RGBA; *glType = GL_HALF_FLOAT; break;
         #else
-        case RL_PIXELFORMAT_UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_LUMINANCE; *glFormat = GL_LUMINANCE; *glType = GL_FLOAT; break;   // NOTE: Requires extension OES_texture_float
-        case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_FLOAT; break;         // NOTE: Requires extension OES_texture_float
-        case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;    // NOTE: Requires extension OES_texture_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_LUMINANCE; *glFormat = GL_LUMINANCE; *glType = GL_FLOAT; break;            // NOTE: Requires extension OES_texture_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_FLOAT; break;                  // NOTE: Requires extension OES_texture_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;             // NOTE: Requires extension OES_texture_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_LUMINANCE; *glFormat = GL_LUMINANCE; *glType = GL_HALF_FLOAT_OES; break;   // NOTE: Requires extension OES_texture_half_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_HALF_FLOAT_OES; break;         // NOTE: Requires extension OES_texture_half_float
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_HALF_FLOAT_OES; break;    // NOTE: Requires extension OES_texture_half_float
         #endif
         #endif
     #elif defined(GRAPHICS_API_OPENGL_33)
@@ -3273,6 +3283,9 @@ void rlGetGlTextureFormats(int format, unsigned int *glInternalFormat, unsigned
         case RL_PIXELFORMAT_UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_R32F; *glFormat = GL_RED; *glType = GL_FLOAT; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB32F; *glFormat = GL_RGB; *glType = GL_FLOAT; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA32F; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_R16F; *glFormat = GL_RED; *glType = GL_HALF_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGB16F; *glFormat = GL_RGB; *glType = GL_HALF_FLOAT; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16: if (RLGL.ExtSupported.texFloat16) *glInternalFormat = GL_RGBA16F; *glFormat = GL_RGBA; *glType = GL_HALF_FLOAT; break;
     #endif
     #if !defined(GRAPHICS_API_OPENGL_11)
         case RL_PIXELFORMAT_COMPRESSED_DXT1_RGB: if (RLGL.ExtSupported.texCompDXT) *glInternalFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT; break;
@@ -4480,6 +4493,9 @@ const char *rlGetPixelFormatName(unsigned int format)
         case RL_PIXELFORMAT_UNCOMPRESSED_R32: return "R32"; break;                     // 32 bpp (1 channel - float)
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: return "R32G32B32"; break;         // 32*3 bpp (3 channels - float)
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: return "R32G32B32A32"; break;   // 32*4 bpp (4 channels - float)
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16: return "R16"; break;                     // 16 bpp (1 channel - half float)
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16: return "R16G16B16"; break;         // 16*3 bpp (3 channels - half float)
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16: return "R16G16B16A16"; break;   // 16*4 bpp (4 channels - half float)
         case RL_PIXELFORMAT_COMPRESSED_DXT1_RGB: return "DXT1_RGB"; break;             // 4 bpp (no alpha)
         case RL_PIXELFORMAT_COMPRESSED_DXT1_RGBA: return "DXT1_RGBA"; break;           // 4 bpp (1 bit alpha)
         case RL_PIXELFORMAT_COMPRESSED_DXT3_RGBA: return "DXT3_RGBA"; break;           // 8 bpp
@@ -4721,6 +4737,9 @@ static int rlGetPixelDataSize(int width, int height, int format)
         case RL_PIXELFORMAT_UNCOMPRESSED_R32: bpp = 32; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32: bpp = 32*3; break;
         case RL_PIXELFORMAT_UNCOMPRESSED_R32G32B32A32: bpp = 32*4; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16: bpp = 16; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16: bpp = 16*3; break;
+        case RL_PIXELFORMAT_UNCOMPRESSED_R16G16B16A16: bpp = 16*4; break;
         case RL_PIXELFORMAT_COMPRESSED_DXT1_RGB:
         case RL_PIXELFORMAT_COMPRESSED_DXT1_RGBA:
         case RL_PIXELFORMAT_COMPRESSED_ETC1_RGB: