Merge pull request #483 from MaikelChan/three_point

Improvements to three point filtering

port/fast3d/gfx_opengl.cpp

@@ -32,6 +32,7 @@ struct ShaderProgram {
     uint8_t num_attribs;
     GLint frame_count_location;
     GLint noise_scale_location;
+    GLint three_point_filter_locations[2];
 };
 
 struct Framebuffer {
@@ -54,6 +55,7 @@ static std::vector<Framebuffer> framebuffers;
 static size_t current_framebuffer;
 static float current_noise_scale;
 static FilteringMode current_filter_mode = FILTER_LINEAR;
+static bool current_linear_filters[2] = {false, false};
 
 static GLenum gl_mirror_clamp = GL_MIRROR_CLAMP_TO_EDGE;
 
@@ -94,6 +96,12 @@ static void gfx_opengl_set_uniforms(struct ShaderProgram* prg) {
     if (prg->noise_scale_location >= 0) {
         glUniform1f(prg->noise_scale_location, current_noise_scale);
     }
+    if (prg->three_point_filter_locations[0] >= 0) {
+        glUniform1i(prg->three_point_filter_locations[0], current_filter_mode == FILTER_THREE_POINT && current_linear_filters[0]);
+    }
+    if (prg->three_point_filter_locations[1] >= 0) {
+        glUniform1i(prg->three_point_filter_locations[1], current_filter_mode == FILTER_THREE_POINT && current_linear_filters[1]);
+    }
 }
 
 static void gfx_opengl_unload_shader(struct ShaderProgram* old_prg) {
@@ -369,9 +377,11 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
     }
     if (cc_features.used_textures[0]) {
         append_line(fs_buf, &fs_len, "uniform sampler2D uTex0;");
+        append_line(fs_buf, &fs_len, "uniform int three_point_filter0;");
     }
     if (cc_features.used_textures[1]) {
         append_line(fs_buf, &fs_len, "uniform sampler2D uTex1;");
+        append_line(fs_buf, &fs_len, "uniform int three_point_filter1;");
     }
 
     append_line(fs_buf, &fs_len, "uniform int frame_count;");
@@ -387,7 +397,7 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
         // used to be two for loops from 0 to 4, but apparently intel drivers crashed trying to unroll it
         // used to have a const weight array, but apparently drivers for the GT620 don't like const array initializers
         append_line(fs_buf, &fs_len, R"(
-            lowp vec4 hookTexture2D(in sampler2D t, in vec2 uv, in vec2 tsize) {
+            lowp vec4 hookTexture2D(in sampler2D t, in vec2 uv, in vec2 tsize, in int three_point_filter) {
                 lowp vec4 cw = vec4(0.0);
                 for (int i = 0; i < 16; ++i) {
                     vec2 xy = vec2(float(i & 3), float(i >> 2));
@@ -397,7 +407,7 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
                 return vec4(cw.rgb / cw.a, 1.0);
             })"
         );
-    } else if (current_filter_mode == FILTER_THREE_POINT) {
+    } else {
 #if __APPLE__
         append_line(fs_buf, &fs_len, "#define TEX_OFFSET(off) texture(tex, texCoord - (off)/texSize)");
 #else
@@ -411,15 +421,11 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
         append_line(fs_buf, &fs_len, "    vec4 c2 = TEX_OFFSET(vec2(offset.x, offset.y - sign(offset.y)));");
         append_line(fs_buf, &fs_len, "    return c0 + abs(offset.x)*(c1-c0) + abs(offset.y)*(c2-c0);");
         append_line(fs_buf, &fs_len, "}");
-        append_line(fs_buf, &fs_len, "vec4 hookTexture2D(in sampler2D tex, in vec2 uv, in vec2 texSize) {");
-        append_line(fs_buf, &fs_len, "    return filter3point(tex, uv, texSize);");
-        append_line(fs_buf, &fs_len, "}");
-    } else {
-        append_line(fs_buf, &fs_len, "vec4 hookTexture2D(in sampler2D tex, in vec2 uv, in vec2 texSize) {");
+        append_line(fs_buf, &fs_len, "vec4 hookTexture2D(in sampler2D tex, in vec2 uv, in vec2 texSize, in int three_point_filter) {");
 #if __APPLE__
-        append_line(fs_buf, &fs_len, "    return texture(tex, uv);");
+        append_line(fs_buf, &fs_len, "    return three_point_filter == 1 ? filter3point(tex, uv, texSize) : texture(tex, uv);");
 #else
-        append_line(fs_buf, &fs_len, "    return texture2D(tex, uv);");
+        append_line(fs_buf, &fs_len, "    return three_point_filter == 1 ? filter3point(tex, uv, texSize) : texture2D(tex, uv);");
 #endif
         append_line(fs_buf, &fs_len, "}");
     }
@@ -461,7 +467,7 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
                 }
             }
 
-            fs_len += sprintf(fs_buf + fs_len, "vec4 texVal%d = hookTexture2D(uTex%d, vTexCoordAdj%d, texSize%d);\n", i, i, i, i);
+            fs_len += sprintf(fs_buf + fs_len, "vec4 texVal%d = hookTexture2D(uTex%d, vTexCoordAdj%d, texSize%d, three_point_filter%d);\n", i, i, i, i, i);
         }
     }
 
@@ -640,6 +646,8 @@ static struct ShaderProgram* gfx_opengl_create_and_load_new_shader(uint64_t shad
 
     prg->frame_count_location = glGetUniformLocation(shader_program, "frame_count");
     prg->noise_scale_location = glGetUniformLocation(shader_program, "noise_scale");
+    prg->three_point_filter_locations[0] = glGetUniformLocation(shader_program, "three_point_filter0");
+    prg->three_point_filter_locations[1] = glGetUniformLocation(shader_program, "three_point_filter1");
 
     gfx_opengl_load_shader(prg);
 
@@ -667,9 +675,11 @@ static void gfx_opengl_delete_texture(uint32_t texID) {
     glDeleteTextures(1, &texID);
 }
 
-static void gfx_opengl_select_texture(int tile, GLuint texture_id) {
+static void gfx_opengl_select_texture(int tile, GLuint texture_id, bool linear_filter) {
     glActiveTexture(GL_TEXTURE0 + tile);
     glBindTexture(GL_TEXTURE_2D, texture_id);
+
+    current_linear_filters[tile] = linear_filter;
 }
 
 static void gfx_opengl_upload_texture(const uint8_t* rgba32_buf, uint32_t width, uint32_t height) {

port/fast3d/gfx_pc.cpp

@@ -522,7 +522,7 @@ static bool gfx_texture_cache_lookup(int i, const TextureCacheKey& key) {
     TextureCacheNode** n = &rendering_state.textures[i];
 
     if (it != gfx_texture_cache.map.end()) {
-        gfx_rapi->select_texture(i, it->second.texture_id);
+        gfx_rapi->select_texture(i, it->second.texture_id, it->second.linear_filter);
         *n = &*it;
         gfx_texture_cache.lru.splice(gfx_texture_cache.lru.end(), gfx_texture_cache.lru,
                                      it->second.lru_location); // move to back
@@ -550,7 +550,7 @@ static bool gfx_texture_cache_lookup(int i, const TextureCacheKey& key) {
     node->second.texture_id = texture_id;
     node->second.lru_location = gfx_texture_cache.lru.insert(gfx_texture_cache.lru.end(), { it });
 
-    gfx_rapi->select_texture(i, texture_id);
+    gfx_rapi->select_texture(i, texture_id, false);
     gfx_rapi->set_sampler_parameters(i, false, 0, 0);
     *n = node;
     return false;

port/fast3d/gfx_rendering_api.h

@@ -24,7 +24,7 @@ struct GfxRenderingAPI {
     struct ShaderProgram* (*lookup_shader)(uint64_t shader_id0, uint32_t shader_id1);
     void (*shader_get_info)(struct ShaderProgram* prg, uint8_t* num_inputs, bool used_textures[2]);
     uint32_t (*new_texture)(void);
-    void (*select_texture)(int tile, uint32_t texture_id);
+    void (*select_texture)(int tile, uint32_t texture_id, bool linear_filter);
     void (*upload_texture)(const uint8_t* rgba32_buf, uint32_t width, uint32_t height);
     void (*set_sampler_parameters)(int sampler, bool linear_filter, uint32_t cms, uint32_t cmt);
     void (*set_depth_mode)(bool depth_test, bool depth_update, bool depth_compare, bool depth_source_prim, uint16_t zmode);

port/src/optionsmenu.c

@@ -702,12 +702,23 @@ static MenuItemHandlerResult menuhandlerMaximizeWindow(s32 operation, struct men
 
 static MenuItemHandlerResult menuhandlerTexFilter(s32 operation, struct menuitem *item, union handlerdata *data)
 {
+	static const char *opts[] = {
+		"Nearest",
+		"Bilinear",
+		"Three Point"
+	};
+
 	switch (operation) {
-	case MENUOP_GET:
-		return (videoGetTextureFilter() != 0);
-	case MENUOP_SET:
-		videoSetTextureFilter(data->checkbox.value);
+	case MENUOP_GETOPTIONCOUNT:
+		data->dropdown.value = ARRAYCOUNT(opts);
 		break;
+	case MENUOP_GETOPTIONTEXT:
+		return (intptr_t)opts[data->dropdown.value];
+	case MENUOP_SET:
+		videoSetTextureFilter(data->dropdown.value);
+		break;
+	case MENUOP_GETSELECTEDINDEX:
+		data->dropdown.value = videoGetTextureFilter();
 	}
 
 	return 0;
@@ -826,7 +837,7 @@ struct menuitem g_ExtendedVideoMenuItems[] = {
 		menuhandlerTexDetail,
 	},
 	{
-		MENUITEMTYPE_CHECKBOX,
+		MENUITEMTYPE_DROPDOWN,
 		0,
 		MENUITEMFLAG_LITERAL_TEXT,
 		(uintptr_t)"Texture Filtering",